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Which continent is highlighted?

social science

A continent is one of the major land masses on the earth. Most people say there are seven continents.

This continent is Africa.

A continent is one of the major land masses on the earth. Most people say there are seven continents. This continent is Africa.

Africa

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Which solution has a higher concentration of yellow particles?

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent

In Solution A and Solution B, the yellow particles represent the solute. To figure out which solution has a higher concentration of yellow particles, look at both the number of yellow particles and the volume of the solvent in each container. Use the concentration formula to find the number of yellow particles per milliliter. Solution A has more yellow particles per milliliter. So, Solution A has a higher concentration of yellow particles.

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent In Solution A and Solution B, the yellow particles represent the solute. To figure out which solution has a higher concentration of yellow particles, look at both the number of yellow particles and the volume of the solvent in each container. Use the concentration formula to find the number of yellow particles per milliliter. Solution A has more yellow particles per milliliter. So, Solution A has a higher concentration of yellow particles.

Solution A

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Which i in column 1?

social science

A grid is made up of lines of squares. They are organized in rows and columns. A grid can help you use a map. A row is a line of squares that goes from side to side. Rows are marked with letters. A column is a line of squares that goes up and down. Columns are marked with numbers.

The park is in column 1.

A grid is made up of lines of squares. They are organized in rows and columns. A grid can help you use a map. A row is a line of squares that goes from side to side. Rows are marked with letters. A column is a line of squares that goes up and down. Columns are marked with numbers. The park is in column 1.

the park

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Which of these states is farthest east?

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.

To find the answer, look at the compass rose. Look at which way the east arrow is pointing. Oklahoma is farthest east.

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map. To find the answer, look at the compass rose. Look at which way the east arrow is pointing. Oklahoma is farthest east.

Oklahoma

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Select the organism in the same species as the green tree frog.

natural science

Scientists use scientific names to identify organisms. Scientific names are made of two words. The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits. A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus. Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus. Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur.

A green tree frog's scientific name is Hyla cinerea. Bufo viridis does not have the same scientific name as a green tree frog. So, Hyla cinerea and Bufo viridis are not in the same species. Hyla cinerea has the same scientific name as a green tree frog. So, these organisms are in the same species. Atelopus zeteki does not have the same scientific name as a green tree frog. So, Hyla cinerea and Atelopus zeteki are not in the same species.

Scientists use scientific names to identify organisms. Scientific names are made of two words. The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits. A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus. Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus. Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur. A green tree frog's scientific name is Hyla cinerea. Bufo viridis does not have the same scientific name as a green tree frog. So, Hyla cinerea and Bufo viridis are not in the same species. Hyla cinerea has the same scientific name as a green tree frog. So, these organisms are in the same species. Atelopus zeteki does not have the same scientific name as a green tree frog. So, Hyla cinerea and Atelopus zeteki are not in the same species.

Hyla cinerea

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What is the direction of this push?

natural science

A force is a push or a pull that one object applies to another. Every force has a direction. The direction of a push is away from the object that is pushing. The direction of a pull is toward the object that is pulling.

The walking man pushes the wheelchair. The direction of the push is away from his hands.

A force is a push or a pull that one object applies to another. Every force has a direction. The direction of a push is away from the object that is pushing. The direction of a pull is toward the object that is pulling. The walking man pushes the wheelchair. The direction of the push is away from his hands.

away from his hands

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Is Oxalis acetosella made up of one cell?

natural science

In the past, scientists classified living organisms into two groups: plants and animals. Over the past 300 years, scientists have discovered many more types of organisms. Today, many scientists classify organisms into six broad groups, called kingdoms. Organisms in each kingdom have specific traits. The table below shows some traits used to describe each kingdom. | Bacteria | Archaea | Protists | Fungi | Animals | Plants How many cells do they have? | one | one | one or many | one or many | many | many Do their cells have a nucleus? | no | no | yes | yes | yes | yes Can their cells make food? | some species can | some species can | some species can | no | no | yes

Oxalis acetosella is a plant. Plants are made up of many cells.

In the past, scientists classified living organisms into two groups: plants and animals. Over the past 300 years, scientists have discovered many more types of organisms. Today, many scientists classify organisms into six broad groups, called kingdoms. Organisms in each kingdom have specific traits. The table below shows some traits used to describe each kingdom. | Bacteria | Archaea | Protists | Fungi | Animals | Plants How many cells do they have? | one | one | one or many | one or many | many | many Do their cells have a nucleus? | no | no | yes | yes | yes | yes Can their cells make food? | some species can | some species can | some species can | no | no | yes Oxalis acetosella is a plant. Plants are made up of many cells.

no

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Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is smaller when the magnets are smaller.

Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The smaller the magnets, the smaller the magnitude of the magnetic force between them. Magnet A is the same size in both pairs. But Magnet B is smaller in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is smaller in Pair 2 than in Pair 1.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is smaller when the magnets are smaller. Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The smaller the magnets, the smaller the magnitude of the magnetic force between them. Magnet A is the same size in both pairs. But Magnet B is smaller in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is smaller in Pair 2 than in Pair 1.

The magnitude of the magnetic force is smaller in Pair 2.

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Compare the average kinetic energies of the particles in each sample. Which sample has the higher temperature?

natural science

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy.

Each particle in sample B has more mass than each particle in sample A. The particles in sample B also have a higher average speed than the particles in sample A. So, the particles in sample B have a higher average kinetic energy than the particles in sample A. Because the particles in sample B have the higher average kinetic energy, sample B must have the higher temperature.

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy. Each particle in sample B has more mass than each particle in sample A. The particles in sample B also have a higher average speed than the particles in sample A. So, the particles in sample B have a higher average kinetic energy than the particles in sample A. Because the particles in sample B have the higher average kinetic energy, sample B must have the higher temperature.

sample B

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Which month has the lowest average precipitation in London?

natural science

Scientists record climate data from places around the world. Precipitation, or rain and snow, is one type of climate data. Scientists collect data over many years. They can use this data to calculate the average precipitation for each month. The average precipitation can be used to describe the climate of a location. A bar graph can be used to show the average amount of precipitation each month. Months with taller bars have more precipitation on average.

To describe the average precipitation trends in London, look at the graph. Choice "May" is incorrect. Choice "Jul" is incorrect. Choice "Nov" is incorrect. July has an average monthly precipitation of about 45 millimeters. This is lower than in any other month. So, July has the lowest average precipitation.

Scientists record climate data from places around the world. Precipitation, or rain and snow, is one type of climate data. Scientists collect data over many years. They can use this data to calculate the average precipitation for each month. The average precipitation can be used to describe the climate of a location. A bar graph can be used to show the average amount of precipitation each month. Months with taller bars have more precipitation on average. To describe the average precipitation trends in London, look at the graph. Choice "May" is incorrect. Choice "Jul" is incorrect. Choice "Nov" is incorrect. July has an average monthly precipitation of about 45 millimeters. This is lower than in any other month. So, July has the lowest average precipitation.

July

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Will these magnets attract or repel each other?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles, called north and south. Here are some examples of magnets. The north pole of each magnet is marked N, and the south pole is marked S. If different poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

Will these magnets attract or repel? To find out, look at which poles are closest to each other. The south pole of one magnet is closest to the north pole of the other magnet. Poles that are different attract. So, these magnets will attract each other.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles, called north and south. Here are some examples of magnets. The north pole of each magnet is marked N, and the south pole is marked S. If different poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same poles are closest to each other, the magnets repel. The magnets in both pairs below repel. Will these magnets attract or repel? To find out, look at which poles are closest to each other. The south pole of one magnet is closest to the north pole of the other magnet. Poles that are different attract. So, these magnets will attract each other.

attract

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Which solution has a higher concentration of blue particles?

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent

In Solution A and Solution B, the blue particles represent the solute. To figure out which solution has a higher concentration of blue particles, look at both the number of blue particles and the volume of the solvent in each container. Use the concentration formula to find the number of blue particles per milliliter. Solution A has more blue particles per milliliter. So, Solution A has a higher concentration of blue particles.

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent In Solution A and Solution B, the blue particles represent the solute. To figure out which solution has a higher concentration of blue particles, look at both the number of blue particles and the volume of the solvent in each container. Use the concentration formula to find the number of blue particles per milliliter. Solution A has more blue particles per milliliter. So, Solution A has a higher concentration of blue particles.

Solution A

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Which property do these three objects have in common?

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification.

Look at each object. For each object, decide if it has that property. A flexible object can be folded or bent without breaking easily. The fries are flexible, but the potato chips are not. A smooth object is not scratchy or rough. The potato chips and the fries are not smooth. Potato chips have a salty taste. All three objects are salty. The property that all three objects have in common is salty.

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification. Look at each object. For each object, decide if it has that property. A flexible object can be folded or bent without breaking easily. The fries are flexible, but the potato chips are not. A smooth object is not scratchy or rough. The potato chips and the fries are not smooth. Potato chips have a salty taste. All three objects are salty. The property that all three objects have in common is salty.

salty

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Select the reptile below.

natural science

Birds, mammals, fish, reptiles, and amphibians are groups of animals. The animals in each group have traits in common. Scientists sort animals into groups based on traits they have in common. This process is called classification.

A coral snake is a reptile. It has scaly, waterproof skin. A giraffe is a mammal. It has hair and feeds its young milk.

Birds, mammals, fish, reptiles, and amphibians are groups of animals. The animals in each group have traits in common. Scientists sort animals into groups based on traits they have in common. This process is called classification. A coral snake is a reptile. It has scaly, waterproof skin. A giraffe is a mammal. It has hair and feeds its young milk.

coral snake

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Which of the following fossils is older? Select the more likely answer.

natural science

A fossil is the preserved evidence of an ancient organism. Some fossils are formed from body parts such as bones or shells. Other fossils, such as footprints or burrows, are formed from traces of an organism's activities. Fossils are typically found in sedimentary rocks. Sedimentary rocks usually form in layers. Over time, new layers are added on top of old layers in a series called a rock sequence. The layers in an undisturbed rock sequence are in the same order as when they formed. So, the deeper layers are older than the shallower layers. The relative ages of fossils can be determined from their positions in an undisturbed rock sequence. Older fossils are usually in deeper layers, and younger fossils are usually in shallower layers.

Look again at the fossils in the rock sequence diagram. Compare the positions of these fossils to determine which one is older: The wood fossil is in a deeper layer in the rock sequence than the ginkgo leaf fossil. So, the wood fossil is most likely older than the ginkgo leaf fossil.

A fossil is the preserved evidence of an ancient organism. Some fossils are formed from body parts such as bones or shells. Other fossils, such as footprints or burrows, are formed from traces of an organism's activities. Fossils are typically found in sedimentary rocks. Sedimentary rocks usually form in layers. Over time, new layers are added on top of old layers in a series called a rock sequence. The layers in an undisturbed rock sequence are in the same order as when they formed. So, the deeper layers are older than the shallower layers. The relative ages of fossils can be determined from their positions in an undisturbed rock sequence. Older fossils are usually in deeper layers, and younger fossils are usually in shallower layers. Look again at the fossils in the rock sequence diagram. Compare the positions of these fossils to determine which one is older: The wood fossil is in a deeper layer in the rock sequence than the ginkgo leaf fossil. So, the wood fossil is most likely older than the ginkgo leaf fossil.

wood

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Which animal is also adapted to be camouflaged among green leaves?

natural science

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The color, texture, and covering of an animal's skin are examples of adaptations. Animals' skins can be adapted in different ways. For example, skin with thick fur might help an animal stay warm. Skin with sharp spines might help an animal defend itself against predators.

Look at the picture of the emerald tree boa. The emerald tree boa has bright green scales covering its body. It is adapted to be camouflaged among green leaves. The word camouflage means to blend in. Now look at each animal. Figure out which animal has a similar adaptation. The green silver-line has a green body. It is adapted to be camouflaged among green leaves. The fire salamander has brightly colored skin. It is not adapted to be camouflaged among green leaves.

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The color, texture, and covering of an animal's skin are examples of adaptations. Animals' skins can be adapted in different ways. For example, skin with thick fur might help an animal stay warm. Skin with sharp spines might help an animal defend itself against predators. Look at the picture of the emerald tree boa. The emerald tree boa has bright green scales covering its body. It is adapted to be camouflaged among green leaves. The word camouflage means to blend in. Now look at each animal. Figure out which animal has a similar adaptation. The green silver-line has a green body. It is adapted to be camouflaged among green leaves. The fire salamander has brightly colored skin. It is not adapted to be camouflaged among green leaves.

green silver-line

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Will these magnets attract or repel each other?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles: north and south. Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

To predict if these magnets will attract or repel, look at which poles are closest to each other. The north pole of one magnet is closest to the south pole of the other magnet. Opposite poles attract. So, these magnets will attract each other.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles: north and south. Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel. To predict if these magnets will attract or repel, look at which poles are closest to each other. The north pole of one magnet is closest to the south pole of the other magnet. Opposite poles attract. So, these magnets will attract each other.

attract

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Which of these states is farthest east?

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.

To find the answer, look at the compass rose. Look at which way the east arrow is pointing. Pennsylvania is farthest east.

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map. To find the answer, look at the compass rose. Look at which way the east arrow is pointing. Pennsylvania is farthest east.

Pennsylvania

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Which material is this coat made of?

natural science

A material is a type of matter. Wood, glass, metal, and plastic are common materials. Some objects are made of just one material. Most nails are made of metal. Other objects are made of more than one material. This hammer is made of metal and wood.

Look at the picture of the coat. The coat is made of two materials. The buckle is made of metal. The rest of the coat is made of wool. Wool comes from the fluffy coats of sheep! First, a farmer cuts the sheep's coats. Then, the wool is spun into yarn. The yarn can be dyed and used to make clothes.

A material is a type of matter. Wood, glass, metal, and plastic are common materials. Some objects are made of just one material. Most nails are made of metal. Other objects are made of more than one material. This hammer is made of metal and wood. Look at the picture of the coat. The coat is made of two materials. The buckle is made of metal. The rest of the coat is made of wool. Wool comes from the fluffy coats of sheep! First, a farmer cuts the sheep's coats. Then, the wool is spun into yarn. The yarn can be dyed and used to make clothes.

metal

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Which of the following organisms is the tertiary consumer in this food web?

natural science

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web.

Tertiary consumers eat secondary consumers. So, in a food web, tertiary consumers have arrows pointing to them from secondary consumers. Secondary consumers have arrows pointing to them from primary consumers. And primary consumers have arrows pointing to them from producers. The copepod has an arrow pointing to it from the rotifer. The rotifer is a secondary consumer, so the copepod is a tertiary consumer. The rotifer has arrows pointing to it from the green algae and the water flea. Neither the green algae nor the water flea is a secondary consumer, so the rotifer is not a tertiary consumer. The black crappie has arrows pointing to it from the rotifer and the shiner. The rotifer and the shiner are secondary consumers, so the black crappie is a tertiary consumer. The green algae does not have any arrows pointing to it, so it is not a tertiary consumer.

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web. Tertiary consumers eat secondary consumers. So, in a food web, tertiary consumers have arrows pointing to them from secondary consumers. Secondary consumers have arrows pointing to them from primary consumers. And primary consumers have arrows pointing to them from producers. The copepod has an arrow pointing to it from the rotifer. The rotifer is a secondary consumer, so the copepod is a tertiary consumer. The rotifer has arrows pointing to it from the green algae and the water flea. Neither the green algae nor the water flea is a secondary consumer, so the rotifer is not a tertiary consumer. The black crappie has arrows pointing to it from the rotifer and the shiner. The rotifer and the shiner are secondary consumers, so the black crappie is a tertiary consumer. The green algae does not have any arrows pointing to it, so it is not a tertiary consumer.

copepod

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Which type of relationship is formed when a megabat eats a fig and drops the fig tree's seeds in a new location?

natural science

When two organisms of different species interact in a way that affects one or both organisms, they form a symbiotic relationship. The word symbiosis comes from a Greek word that means living together. Scientists define types of symbiotic relationships based on how each organism is affected. This table lists three common types of symbiotic relationships. It shows how each organism is affected in each type of symbiotic relationship. Type of symbiotic relationship | Organism of one species... | Organism of the other species... Commensal | benefits | is not significantly affected Mutualistic | benefits | benefits Parasitic | benefits | is harmed (but not usually killed)

When a megabat eats a fig, the megabat gets the food it needs to survive and grow. So the megabat benefits from its relationship with the fig tree. Both the fig tree and its seeds have a better chance of surviving when the bat moves the seeds to a new location. So, the fig tree also benefits from its relationship with the megabat. Since both the megabat and the fig tree benefit, a mutualistic relationship is formed when a megabat eats a fig and drops the fig tree's seeds in a new location.

When two organisms of different species interact in a way that affects one or both organisms, they form a symbiotic relationship. The word symbiosis comes from a Greek word that means living together. Scientists define types of symbiotic relationships based on how each organism is affected. This table lists three common types of symbiotic relationships. It shows how each organism is affected in each type of symbiotic relationship. Type of symbiotic relationship | Organism of one species... | Organism of the other species... Commensal | benefits | is not significantly affected Mutualistic | benefits | benefits Parasitic | benefits | is harmed (but not usually killed) When a megabat eats a fig, the megabat gets the food it needs to survive and grow. So the megabat benefits from its relationship with the fig tree. Both the fig tree and its seeds have a better chance of surviving when the bat moves the seeds to a new location. So, the fig tree also benefits from its relationship with the megabat. Since both the megabat and the fig tree benefit, a mutualistic relationship is formed when a megabat eats a fig and drops the fig tree's seeds in a new location.

mutualistic

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Select the mammal below.

natural science

Birds, mammals, fish, reptiles, and amphibians are groups of animals. The animals in each group have traits in common. Scientists sort animals into groups based on traits they have in common. This process is called classification.

A green tree frog is an amphibian. It has moist skin and begins its life in water. There are many kinds of tree frogs. Most tree frogs are very small. They can walk on thin branches. A giraffe is a mammal. It has hair and feeds its young milk. Giraffes eat mostly leaves that are too high up for other animals to reach.

Birds, mammals, fish, reptiles, and amphibians are groups of animals. The animals in each group have traits in common. Scientists sort animals into groups based on traits they have in common. This process is called classification. A green tree frog is an amphibian. It has moist skin and begins its life in water. There are many kinds of tree frogs. Most tree frogs are very small. They can walk on thin branches. A giraffe is a mammal. It has hair and feeds its young milk. Giraffes eat mostly leaves that are too high up for other animals to reach.

giraffe

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Select the organism in the same species as the pink-backed pelican.

natural science

Scientists use scientific names to identify organisms. Scientific names are made of two words. The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits. A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus. Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus. Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur.

A pink-backed pelican's scientific name is Pelecanus rufescens. Pelecanus rufescens has the same scientific name as a pink-backed pelican. So, these organisms are in the same species. Strix uralensis does not have the same scientific name as a pink-backed pelican. So, Pelecanus rufescens and Strix uralensis are not in the same species. Ardea cinerea does not have the same scientific name as a pink-backed pelican. So, Pelecanus rufescens and Ardea cinerea are not in the same species.

Scientists use scientific names to identify organisms. Scientific names are made of two words. The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits. A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus. Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus. Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur. A pink-backed pelican's scientific name is Pelecanus rufescens. Pelecanus rufescens has the same scientific name as a pink-backed pelican. So, these organisms are in the same species. Strix uralensis does not have the same scientific name as a pink-backed pelican. So, Pelecanus rufescens and Strix uralensis are not in the same species. Ardea cinerea does not have the same scientific name as a pink-backed pelican. So, Pelecanus rufescens and Ardea cinerea are not in the same species.

Pelecanus rufescens

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Which of these states is farthest north?

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.

To find the answer, look at the compass rose. Look at which way the north arrow is pointing. Michigan is farthest north.

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map. To find the answer, look at the compass rose. Look at which way the north arrow is pointing. Michigan is farthest north.

Michigan

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Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by changing the distance between them. The magnitude of the magnetic force is smaller when there is a greater distance between the magnets.

Distance affects the magnitude of the magnetic force. When there is a greater distance between magnets, the magnitude of the magnetic force between them is smaller. There is a greater distance between the magnets in Pair 1 than in Pair 2. So, the magnitude of the magnetic force is smaller in Pair 1 than in Pair 2.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by changing the distance between them. The magnitude of the magnetic force is smaller when there is a greater distance between the magnets. Distance affects the magnitude of the magnetic force. When there is a greater distance between magnets, the magnitude of the magnetic force between them is smaller. There is a greater distance between the magnets in Pair 1 than in Pair 2. So, the magnitude of the magnetic force is smaller in Pair 1 than in Pair 2.

The magnitude of the magnetic force is smaller in Pair 1.

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What is the expected ratio of offspring with a white body to offspring with a brown body? Choose the most likely ratio.

natural science

Offspring phenotypes: dominant or recessive? How do you determine an organism's phenotype for a trait? Look at the combination of alleles in the organism's genotype for the gene that affects that trait. Some alleles have types called dominant and recessive. These two types can cause different versions of the trait to appear as the organism's phenotype. If an organism's genotype has at least one dominant allele for a gene, the organism's phenotype will be the dominant allele's version of the gene's trait. If an organism's genotype has only recessive alleles for a gene, the organism's phenotype will be the recessive allele's version of the gene's trait. A Punnett square shows what types of offspring a cross can produce. The expected ratio of offspring types compares how often the cross produces each type of offspring, on average. To write this ratio, count the number of boxes in the Punnett square representing each type. For example, consider the Punnett square below. | F | f F | FF | Ff f | Ff | ff There is 1 box with the genotype FF and 2 boxes with the genotype Ff. So, the expected ratio of offspring with the genotype FF to those with Ff is 1:2.

To determine how many boxes in the Punnett square represent offspring with a white body or a brown body, consider whether each phenotype is the dominant or recessive allele's version of the body color trait. The question tells you that the b allele, which is for a white body, is recessive to the B allele, which is for a brown body. A white body is the recessive allele's version of the body color trait. A Channel catfish with the recessive version of the body color trait must have only recessive alleles for the body color gene. So, offspring with a white body must have the genotype bb. There are 0 boxes in the Punnett square with the genotype bb. A brown body is the dominant allele's version of the body color trait. A Channel catfish with the dominant version of the body color trait must have at least one dominant allele for the body color gene. So, offspring with a brown body must have the genotype BB or Bb. All 4 boxes in the Punnett square have the genotype BB or Bb. So, the expected ratio of offspring with a white body to offspring with a brown body is 0:4. This means that, based on the Punnett square, this cross will never produce offspring with a white body. Instead, this cross is expected to always produce offspring with a brown body.

Offspring phenotypes: dominant or recessive? How do you determine an organism's phenotype for a trait? Look at the combination of alleles in the organism's genotype for the gene that affects that trait. Some alleles have types called dominant and recessive. These two types can cause different versions of the trait to appear as the organism's phenotype. If an organism's genotype has at least one dominant allele for a gene, the organism's phenotype will be the dominant allele's version of the gene's trait. If an organism's genotype has only recessive alleles for a gene, the organism's phenotype will be the recessive allele's version of the gene's trait. A Punnett square shows what types of offspring a cross can produce. The expected ratio of offspring types compares how often the cross produces each type of offspring, on average. To write this ratio, count the number of boxes in the Punnett square representing each type. For example, consider the Punnett square below. | F | f F | FF | Ff f | Ff | ff There is 1 box with the genotype FF and 2 boxes with the genotype Ff. So, the expected ratio of offspring with the genotype FF to those with Ff is 1:2. To determine how many boxes in the Punnett square represent offspring with a white body or a brown body, consider whether each phenotype is the dominant or recessive allele's version of the body color trait. The question tells you that the b allele, which is for a white body, is recessive to the B allele, which is for a brown body. A white body is the recessive allele's version of the body color trait. A Channel catfish with the recessive version of the body color trait must have only recessive alleles for the body color gene. So, offspring with a white body must have the genotype bb. There are 0 boxes in the Punnett square with the genotype bb. A brown body is the dominant allele's version of the body color trait. A Channel catfish with the dominant version of the body color trait must have at least one dominant allele for the body color gene. So, offspring with a brown body must have the genotype BB or Bb. All 4 boxes in the Punnett square have the genotype BB or Bb. So, the expected ratio of offspring with a white body to offspring with a brown body is 0:4. This means that, based on the Punnett square, this cross will never produce offspring with a white body. Instead, this cross is expected to always produce offspring with a brown body.

0:4

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Is a pair of jeans a solid, a liquid, or a gas?

natural science

Solid, liquid, and gas are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms. When matter is a solid, it has a definite volume and a definite shape. So, a solid has a size and shape of its own. Some solids can be easily folded, bent, or broken. A piece of paper is a solid. Also, some solids are very small. A grain of sand is a solid. When matter is a liquid, it has a definite volume but not a definite shape. So, a liquid has a size of its own, but it does not have a shape of its own. Think about pouring juice from a bottle into a cup. The juice still takes up the same amount of space, but it takes the shape of the bottle. Some liquids are thicker than others. Honey and milk are both liquids. But pouring honey takes more time than pouring milk. When matter is a gas, it does not have a definite volume or a definite shape. A gas expands, or gets bigger, until it completely fills a space. A gas can also get smaller if it is squeezed into a smaller space. Many gases are invisible. The oxygen you breathe is a gas. The helium in a balloon is also a gas.

A pair of jeans is a solid. You can fold a pair of jeans. But it will still have a size and shape of its own.

Solid, liquid, and gas are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms. When matter is a solid, it has a definite volume and a definite shape. So, a solid has a size and shape of its own. Some solids can be easily folded, bent, or broken. A piece of paper is a solid. Also, some solids are very small. A grain of sand is a solid. When matter is a liquid, it has a definite volume but not a definite shape. So, a liquid has a size of its own, but it does not have a shape of its own. Think about pouring juice from a bottle into a cup. The juice still takes up the same amount of space, but it takes the shape of the bottle. Some liquids are thicker than others. Honey and milk are both liquids. But pouring honey takes more time than pouring milk. When matter is a gas, it does not have a definite volume or a definite shape. A gas expands, or gets bigger, until it completely fills a space. A gas can also get smaller if it is squeezed into a smaller space. Many gases are invisible. The oxygen you breathe is a gas. The helium in a balloon is also a gas. A pair of jeans is a solid. You can fold a pair of jeans. But it will still have a size and shape of its own.

a solid

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Which type of force from the uncle slides the sled along behind him?

natural science

A force is a push or a pull that one object applies to a second object. The direction of a push is away from the object that is pushing. The direction of a pull is toward the object that is pulling.

The uncle applies a force to the rope on the sled. The sled slides along behind him. The direction of this force is toward the uncle. This force is a pull.

A force is a push or a pull that one object applies to a second object. The direction of a push is away from the object that is pushing. The direction of a pull is toward the object that is pulling. The uncle applies a force to the rope on the sled. The sled slides along behind him. The direction of this force is toward the uncle. This force is a pull.

pull

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Which i in row C?

social science

A grid is made up of lines of squares. They are organized in rows and columns. A grid can help you use a map. A row is a line of squares that goes from side to side. Rows are marked with letters. A column is a line of squares that goes up and down. Columns are marked with numbers.

The restaurant is in row C.

A grid is made up of lines of squares. They are organized in rows and columns. A grid can help you use a map. A row is a line of squares that goes from side to side. Rows are marked with letters. A column is a line of squares that goes up and down. Columns are marked with numbers. The restaurant is in row C.

the restaurant

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Will these magnets attract or repel each other?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles: north and south. Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

To predict if these magnets will attract or repel, look at which poles are closest to each other. The north pole of one magnet is closest to the north pole of the other magnet. Like poles repel. So, these magnets will repel each other.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles: north and south. Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel. To predict if these magnets will attract or repel, look at which poles are closest to each other. The north pole of one magnet is closest to the north pole of the other magnet. Like poles repel. So, these magnets will repel each other.

repel

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Which of these oceans does the prime meridian intersect?

social science

Lines of latitude and lines of longitude are imaginary lines drawn on some globes and maps. They can help you find places on globes and maps. Lines of latitude show how far north or south a place is. We use units called degrees to describe how far a place is from the equator. The equator is the line located at 0° latitude. We start counting degrees from there. Lines north of the equator are labeled N for north. Lines south of the equator are labeled S for south. Lines of latitude are also called parallels because each line is parallel to the equator. Lines of longitude are also called meridians. They show how far east or west a place is. We use degrees to help describe how far a place is from the prime meridian. The prime meridian is the line located at 0° longitude. Lines west of the prime meridian are labeled W. Lines east of the prime meridian are labeled E. Meridians meet at the north and south poles. The equator goes all the way around the earth, but the prime meridian is different. It only goes from the North Pole to the South Pole on one side of the earth. On the opposite side of the globe is another special meridian. It is labeled both 180°E and 180°W. Together, lines of latitude and lines of longitude form a grid. You can use this grid to find the exact location of a place.

The prime meridian is the line at 0° longitude. It intersects the Arctic Ocean. It does not intersect the Pacific Ocean or the Indian Ocean.

Lines of latitude and lines of longitude are imaginary lines drawn on some globes and maps. They can help you find places on globes and maps. Lines of latitude show how far north or south a place is. We use units called degrees to describe how far a place is from the equator. The equator is the line located at 0° latitude. We start counting degrees from there. Lines north of the equator are labeled N for north. Lines south of the equator are labeled S for south. Lines of latitude are also called parallels because each line is parallel to the equator. Lines of longitude are also called meridians. They show how far east or west a place is. We use degrees to help describe how far a place is from the prime meridian. The prime meridian is the line located at 0° longitude. Lines west of the prime meridian are labeled W. Lines east of the prime meridian are labeled E. Meridians meet at the north and south poles. The equator goes all the way around the earth, but the prime meridian is different. It only goes from the North Pole to the South Pole on one side of the earth. On the opposite side of the globe is another special meridian. It is labeled both 180°E and 180°W. Together, lines of latitude and lines of longitude form a grid. You can use this grid to find the exact location of a place. The prime meridian is the line at 0° longitude. It intersects the Arctic Ocean. It does not intersect the Pacific Ocean or the Indian Ocean.

the Arctic Ocean

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Select the bird below.

natural science

Birds, mammals, fish, reptiles, and amphibians are groups of animals. The animals in each group have traits in common. Scientists sort animals into groups based on traits they have in common. This process is called classification.

A pelican is a bird. It has feathers, two wings, and a beak. An African bullfrog is an amphibian. It has moist skin and begins its life in water.

Birds, mammals, fish, reptiles, and amphibians are groups of animals. The animals in each group have traits in common. Scientists sort animals into groups based on traits they have in common. This process is called classification. A pelican is a bird. It has feathers, two wings, and a beak. An African bullfrog is an amphibian. It has moist skin and begins its life in water.

pelican

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Is the following statement about our solar system true or false? The volume of Earth is more than ten times the volume of Mercury.

natural science

A planet's volume tells you the size of the planet. The primary composition of a planet is what the planet is made mainly of. In our solar system, planets are made mainly of rock, gas, or ice. The volume of a planet is a very large quantity. Large quantities such as this are often written in scientific notation. For example, the volume of Jupiter is 1,430,000,000,000,000 km^3. In scientific notation, Jupiter's volume is written as 1.43 x 10^15 km^3. To compare two numbers written in scientific notation, first compare their exponents. The bigger the exponent is, the bigger the number is. For example: 1.43 x 10^15 is larger than 1.43 x 10^12 If their exponents are equal, compare the first numbers. For example: 1.43 x 10^15 is larger than 1.25 x 10^15 To multiply a number written in scientific notation by a power of 10, write the multiple of 10 as 10 raised to an exponent. Then, add the exponents. For example: 1.43 x 10^15 · 1000 = 1.43 x 10^15 · 10^3 = 1.43 x 10^(15 + 3) = 1.43 x 10^18

To determine if this statement is true, calculate the value of ten times the volume of Mercury. Then compare the result to the volume of Earth. The volume of Earth is 1.08 x 10^12 km^3, which is greater than 6.08 x 10^11 km^3. So, the volume of Earth is more than ten times the volume of Mercury.

A planet's volume tells you the size of the planet. The primary composition of a planet is what the planet is made mainly of. In our solar system, planets are made mainly of rock, gas, or ice. The volume of a planet is a very large quantity. Large quantities such as this are often written in scientific notation. For example, the volume of Jupiter is 1,430,000,000,000,000 km^3. In scientific notation, Jupiter's volume is written as 1.43 x 10^15 km^3. To compare two numbers written in scientific notation, first compare their exponents. The bigger the exponent is, the bigger the number is. For example: 1.43 x 10^15 is larger than 1.43 x 10^12 If their exponents are equal, compare the first numbers. For example: 1.43 x 10^15 is larger than 1.25 x 10^15 To multiply a number written in scientific notation by a power of 10, write the multiple of 10 as 10 raised to an exponent. Then, add the exponents. For example: 1.43 x 10^15 · 1000 = 1.43 x 10^15 · 10^3 = 1.43 x 10^(15 + 3) = 1.43 x 10^18 To determine if this statement is true, calculate the value of ten times the volume of Mercury. Then compare the result to the volume of Earth. The volume of Earth is 1.08 x 10^12 km^3, which is greater than 6.08 x 10^11 km^3. So, the volume of Earth is more than ten times the volume of Mercury.

true

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Is a rubber duck a solid or a liquid?

natural science

Solid and liquid are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms. When matter is a solid, it has a shape of its own. Some solids can be bent or broken easily. Others are hard to bend or break. A glass cup is a solid. A sock is also a solid. When matter is a liquid, it takes the shape of its container. Think about pouring a liquid from a cup into a bottle. The shape of the liquid is different in the cup than in the bottle. But the liquid still takes up the same amount of space. Juice is a liquid. Honey is also a liquid.

A rubber duck is a solid. You can squeeze a rubber duck. But it will still have a size and shape of its own.

Solid and liquid are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms. When matter is a solid, it has a shape of its own. Some solids can be bent or broken easily. Others are hard to bend or break. A glass cup is a solid. A sock is also a solid. When matter is a liquid, it takes the shape of its container. Think about pouring a liquid from a cup into a bottle. The shape of the liquid is different in the cup than in the bottle. But the liquid still takes up the same amount of space. Juice is a liquid. Honey is also a liquid. A rubber duck is a solid. You can squeeze a rubber duck. But it will still have a size and shape of its own.

a solid

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Which of these states is farthest west?

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.

To find the answer, look at the compass rose. Look at which way the west arrow is pointing. North Dakota is farthest west.

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map. To find the answer, look at the compass rose. Look at which way the west arrow is pointing. North Dakota is farthest west.

North Dakota

7c7acbe398514e6193110a9d229eec53

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Which of the following fossils is younger? Select the more likely answer.

natural science

A fossil is the preserved evidence of an ancient organism. Some fossils are formed from body parts such as bones or shells. Other fossils, such as footprints or burrows, are formed from traces of an organism's activities. Fossils are typically found in sedimentary rocks. Sedimentary rocks usually form in layers. Over time, new layers are added on top of old layers in a series called a rock sequence. The layers in an undisturbed rock sequence are in the same order as when they formed. So, the deeper layers are older than the shallower layers. The relative ages of fossils can be determined from their positions in an undisturbed rock sequence. Older fossils are usually in deeper layers, and younger fossils are usually in shallower layers.

Look again at the fossils in the rock sequence diagram. Compare the positions of these fossils to determine which one is younger: The mammal tooth fossil is in a shallower layer in the rock sequence than the wood fossil. So, the mammal tooth fossil is most likely younger than the wood fossil.

A fossil is the preserved evidence of an ancient organism. Some fossils are formed from body parts such as bones or shells. Other fossils, such as footprints or burrows, are formed from traces of an organism's activities. Fossils are typically found in sedimentary rocks. Sedimentary rocks usually form in layers. Over time, new layers are added on top of old layers in a series called a rock sequence. The layers in an undisturbed rock sequence are in the same order as when they formed. So, the deeper layers are older than the shallower layers. The relative ages of fossils can be determined from their positions in an undisturbed rock sequence. Older fossils are usually in deeper layers, and younger fossils are usually in shallower layers. Look again at the fossils in the rock sequence diagram. Compare the positions of these fossils to determine which one is younger: The mammal tooth fossil is in a shallower layer in the rock sequence than the wood fossil. So, the mammal tooth fossil is most likely younger than the wood fossil.

mammal tooth

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Which property do these three objects have in common?

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups.

Look at each object. For each object, decide if it has that property. A bumpy object is covered in lumps and bumps. All three objects are bumpy. A stretchy object gets longer when you pull on it. None of the objects are stretchy. A colorful object has one or more bright colors. The gold nugget is colorful, but the pretzel and the log are not. The property that all three objects have in common is bumpy.

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups. Look at each object. For each object, decide if it has that property. A bumpy object is covered in lumps and bumps. All three objects are bumpy. A stretchy object gets longer when you pull on it. None of the objects are stretchy. A colorful object has one or more bright colors. The gold nugget is colorful, but the pretzel and the log are not. The property that all three objects have in common is bumpy.

bumpy

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Which of these states is farthest north?

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.

To find the answer, look at the compass rose. Look at which way the north arrow is pointing. Minnesota is farthest north.

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map. To find the answer, look at the compass rose. Look at which way the north arrow is pointing. Minnesota is farthest north.

Minnesota

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Compare the average kinetic energies of the particles in each sample. Which sample has the higher temperature?

natural science

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy.

Each particle in sample A has more mass than each particle in sample B. The particles in sample A also have a higher average speed than the particles in sample B. So, the particles in sample A have a higher average kinetic energy than the particles in sample B. Because the particles in sample A have the higher average kinetic energy, sample A must have the higher temperature.

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy. Each particle in sample A has more mass than each particle in sample B. The particles in sample A also have a higher average speed than the particles in sample B. So, the particles in sample A have a higher average kinetic energy than the particles in sample B. Because the particles in sample A have the higher average kinetic energy, sample A must have the higher temperature.

sample A

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Will these magnets attract or repel each other?

natural science

Magnets can pull or push on other magnets without touching them. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes are called magnetic forces. Magnetic forces are strongest at the magnets' poles, or ends. Every magnet has two poles: a north pole (N) and a south pole (S). Here are some examples of magnets. Their poles are shown in different colors and labeled. Whether a magnet attracts or repels other magnets depends on the positions of its poles. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

To predict if these magnets will attract or repel, look at which poles are closest to each other. The south pole of one magnet is closest to the south pole of the other magnet. Like poles repel. So, these magnets will repel each other.

Magnets can pull or push on other magnets without touching them. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes are called magnetic forces. Magnetic forces are strongest at the magnets' poles, or ends. Every magnet has two poles: a north pole (N) and a south pole (S). Here are some examples of magnets. Their poles are shown in different colors and labeled. Whether a magnet attracts or repels other magnets depends on the positions of its poles. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel. To predict if these magnets will attract or repel, look at which poles are closest to each other. The south pole of one magnet is closest to the south pole of the other magnet. Like poles repel. So, these magnets will repel each other.

repel

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Which better describes the Taklamakan Desert ecosystem?

natural science

An environment includes all of the biotic, or living, and abiotic, or nonliving, things in an area. An ecosystem is created by the relationships that form among the biotic and abiotic parts of an environment. There are many different types of terrestrial, or land-based, ecosystems. Here are some ways in which terrestrial ecosystems can differ from each other: the pattern of weather, or climate the type of soil the organisms that live there

A cold desert is a type of ecosystem. Cold deserts have the following features: a small amount of rain or snow, dry, thin soil, and long, cold winters. So, the Taklamakan Desert has long, cold winters. It also has a small amount of rain or snow.

An environment includes all of the biotic, or living, and abiotic, or nonliving, things in an area. An ecosystem is created by the relationships that form among the biotic and abiotic parts of an environment. There are many different types of terrestrial, or land-based, ecosystems. Here are some ways in which terrestrial ecosystems can differ from each other: the pattern of weather, or climate the type of soil the organisms that live there A cold desert is a type of ecosystem. Cold deserts have the following features: a small amount of rain or snow, dry, thin soil, and long, cold winters. So, the Taklamakan Desert has long, cold winters. It also has a small amount of rain or snow.

It has long, cold winters. It also has a small amount of rain or snow.

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Compare the average kinetic energies of the particles in each sample. Which sample has the higher temperature?

natural science

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy.

The particles in both samples have the same average speed, but each particle in sample A has more mass than each particle in sample B. So, the particles in sample A have a higher average kinetic energy than the particles in sample B. Because the particles in sample A have the higher average kinetic energy, sample A must have the higher temperature.

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy. The particles in both samples have the same average speed, but each particle in sample A has more mass than each particle in sample B. So, the particles in sample A have a higher average kinetic energy than the particles in sample B. Because the particles in sample A have the higher average kinetic energy, sample A must have the higher temperature.

sample A

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Which plant can produce eggs and sperm?

natural science

Fern plants reproduce using both asexual reproduction and sexual reproduction. Mature ferns have flat leaves called fronds. Ferns have structures that look like small dots on the underside of their fronds. These structures are called spore cases. The mature ferns use asexual reproduction to make spores. When the spore cases open, the spores are released. When a spore lands on the ground and germinates, it grows into a small heart-shaped plant. The heart-shaped plant begins the fern's sexual reproduction stage by making eggs and sperm. Ferns live in damp environments, and sperm can swim though small water drops. Self-fertilization happens when a sperm swims to an egg on the same heart-shaped plant. Cross-fertilization happens when the sperm swims to an egg on a nearby plant. Fertilization happens when a sperm and an egg fuse. The fertilized egg germinates and grows into a mature fern. The mature fern can make spores and begin the fern life cycle again.

A heart-shaped plant can produce eggs and sperm. A mature fern produces spores, not eggs and sperm.

Fern plants reproduce using both asexual reproduction and sexual reproduction. Mature ferns have flat leaves called fronds. Ferns have structures that look like small dots on the underside of their fronds. These structures are called spore cases. The mature ferns use asexual reproduction to make spores. When the spore cases open, the spores are released. When a spore lands on the ground and germinates, it grows into a small heart-shaped plant. The heart-shaped plant begins the fern's sexual reproduction stage by making eggs and sperm. Ferns live in damp environments, and sperm can swim though small water drops. Self-fertilization happens when a sperm swims to an egg on the same heart-shaped plant. Cross-fertilization happens when the sperm swims to an egg on a nearby plant. Fertilization happens when a sperm and an egg fuse. The fertilized egg germinates and grows into a mature fern. The mature fern can make spores and begin the fern life cycle again. A heart-shaped plant can produce eggs and sperm. A mature fern produces spores, not eggs and sperm.

a heart-shaped plant

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Complete the statement. Bromomethane is ().

natural science

All substances are made of one or more chemical elements, or types of atoms. Substances that are made of only one chemical element are elementary substances. Substances that are made of two or more chemical elements bonded together are compounds. Every chemical element is represented by its own symbol. For some elements, the symbol is one capital letter. For other elements, the symbol is one capital letter and one lowercase letter. For example, the symbol for the chemical element boron is B, and the symbol for the chemical element chlorine is Cl. Scientists can use models to represent molecules. A ball-and-stick model of a molecule is shown below. This model represents a molecule of the compound boron trichloride. In a ball-and-stick model, the balls represent atoms, and the sticks represent chemical bonds. Notice how each ball is labeled with a symbol for a chemical element. The ball represents one atom of that element.

Count the number of chemical elements represented in the model. Then, decide if bromomethane is an elementary substance or a compound. In this model, each ball is labeled with C for carbon, H for hydrogen, or Br for bromine. So, the model shows you that bromomethane is made of three chemical elements bonded together. Substances made of two or more chemical elements bonded together are compounds. So, bromomethane is a compound.

All substances are made of one or more chemical elements, or types of atoms. Substances that are made of only one chemical element are elementary substances. Substances that are made of two or more chemical elements bonded together are compounds. Every chemical element is represented by its own symbol. For some elements, the symbol is one capital letter. For other elements, the symbol is one capital letter and one lowercase letter. For example, the symbol for the chemical element boron is B, and the symbol for the chemical element chlorine is Cl. Scientists can use models to represent molecules. A ball-and-stick model of a molecule is shown below. This model represents a molecule of the compound boron trichloride. In a ball-and-stick model, the balls represent atoms, and the sticks represent chemical bonds. Notice how each ball is labeled with a symbol for a chemical element. The ball represents one atom of that element. Count the number of chemical elements represented in the model. Then, decide if bromomethane is an elementary substance or a compound. In this model, each ball is labeled with C for carbon, H for hydrogen, or Br for bromine. So, the model shows you that bromomethane is made of three chemical elements bonded together. Substances made of two or more chemical elements bonded together are compounds. So, bromomethane is a compound.

a compound

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Which better describes the Peary Land ecosystem?

natural science

An environment includes all of the biotic, or living, and abiotic, or nonliving, things in an area. An ecosystem is created by the relationships that form among the biotic and abiotic parts of an environment. There are many different types of terrestrial, or land-based, ecosystems. Here are some ways in which terrestrial ecosystems can differ from each other: the pattern of weather, or climate the type of soil the organisms that live there

A tundra is a type of ecosystem. Tundras have the following features: long, cold winters and short, cold summers, soil that is frozen year-round, and mostly small plants. So, Peary Land has mostly small plants. It also has short, cool summers.

An environment includes all of the biotic, or living, and abiotic, or nonliving, things in an area. An ecosystem is created by the relationships that form among the biotic and abiotic parts of an environment. There are many different types of terrestrial, or land-based, ecosystems. Here are some ways in which terrestrial ecosystems can differ from each other: the pattern of weather, or climate the type of soil the organisms that live there A tundra is a type of ecosystem. Tundras have the following features: long, cold winters and short, cold summers, soil that is frozen year-round, and mostly small plants. So, Peary Land has mostly small plants. It also has short, cool summers.

It has mostly small plants. It also has short, cold summers.

a1272fa986f44f3a97ad9294615ff492

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Which part of an apple tree can make seeds?

natural science

Flowering plants, called angiosperms, use their flowers for sexual reproduction. Flowers can have male parts, female parts, or both! The male part is called the stamen, and the female part is called the pistil. Both the male and female parts are needed for sexual reproduction. The female part produces eggs, and the male part produces pollen. Pollen contains cells that become sperm. Pollination happens when pollen lands on top of the pistil. Self-pollination happens when a plant with both male and female parts pollinates itself. Cross-pollination happens when pollen from one plant lands on the pistil of a flower on a different plant. Animals, including birds and insects, can be pollinators. Many pollinators come to flowers to get food. As a pollinator feeds, it moves pollen from one flower to another. After pollination, sperm from the pollen fuse with eggs. This is called fertilization. The fertilized eggs then grow into seeds. When a seed lands on the ground, it can germinate and grow into a new plant. The new plant can grow flowers and begin the angiosperm plant life cycle again.

An apple tree's flowers can make seeds. Inside a flower, a sperm cell and an egg fuse to make a fertilized egg. The fertilized egg grows into a seed. The fruit grows from the ovary around the seeds. But the fruit does not make the seeds.

Flowering plants, called angiosperms, use their flowers for sexual reproduction. Flowers can have male parts, female parts, or both! The male part is called the stamen, and the female part is called the pistil. Both the male and female parts are needed for sexual reproduction. The female part produces eggs, and the male part produces pollen. Pollen contains cells that become sperm. Pollination happens when pollen lands on top of the pistil. Self-pollination happens when a plant with both male and female parts pollinates itself. Cross-pollination happens when pollen from one plant lands on the pistil of a flower on a different plant. Animals, including birds and insects, can be pollinators. Many pollinators come to flowers to get food. As a pollinator feeds, it moves pollen from one flower to another. After pollination, sperm from the pollen fuse with eggs. This is called fertilization. The fertilized eggs then grow into seeds. When a seed lands on the ground, it can germinate and grow into a new plant. The new plant can grow flowers and begin the angiosperm plant life cycle again. An apple tree's flowers can make seeds. Inside a flower, a sperm cell and an egg fuse to make a fertilized egg. The fertilized egg grows into a seed. The fruit grows from the ovary around the seeds. But the fruit does not make the seeds.

the flowers

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Which animal's mouth is also adapted to tear through meat?

natural science

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The shape of an animal's mouth is one example of an adaptation. Animals' mouths can be adapted in different ways. For example, a large mouth with sharp teeth might help an animal tear through meat. A long, thin mouth might help an animal catch insects that live in holes. Animals that eat similar food often have similar mouths.

Look at the picture of the Eurasian lynx. The Eurasian lynx has a large mouth and sharp teeth. Its mouth is adapted to tear through meat. The Eurasian lynx uses its large mouth to grab its prey. It uses its sharp teeth to cut up the meat of the prey into pieces it can swallow. Now look at each animal. Figure out which animal has a similar adaptation. The tiger has a large mouth and sharp teeth. Its mouth is adapted to tear through meat. The marmot has large front teeth. It does not have sharp teeth. So, its mouth is not adapted to tear through meat. The marmot uses its mouth to gnaw on plant matter.

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The shape of an animal's mouth is one example of an adaptation. Animals' mouths can be adapted in different ways. For example, a large mouth with sharp teeth might help an animal tear through meat. A long, thin mouth might help an animal catch insects that live in holes. Animals that eat similar food often have similar mouths. Look at the picture of the Eurasian lynx. The Eurasian lynx has a large mouth and sharp teeth. Its mouth is adapted to tear through meat. The Eurasian lynx uses its large mouth to grab its prey. It uses its sharp teeth to cut up the meat of the prey into pieces it can swallow. Now look at each animal. Figure out which animal has a similar adaptation. The tiger has a large mouth and sharp teeth. Its mouth is adapted to tear through meat. The marmot has large front teeth. It does not have sharp teeth. So, its mouth is not adapted to tear through meat. The marmot uses its mouth to gnaw on plant matter.

tiger

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In this food web, which organism contains matter that eventually moves to the bat star?

natural science

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web.

Use the arrows to follow how matter moves through this food web. For each answer choice, try to find a path of arrows to the bat star. The only arrow pointing from the sea otter leads to the orca. The only arrow pointing from the orca leads to the sea cucumber. No arrows point from the sea cucumber to any other organisms. So, in this food web, matter does not move from the sea otter to the bat star.There are three paths matter can take from the zooplankton to the bat star: zooplankton->kelp bass->bat star. zooplankton->plainfin midshipman->kelp bass->bat star. zooplankton->black rockfish->kelp bass->bat star. There is one path matter can take from the kelp to the bat star: kelp->kelp bass->bat star. orca. The only arrow pointing from the orca leads to the sea cucumber. No arrows point from the sea cucumber to any other organisms. So, in this food web, matter does not move from the orca to the bat star..

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web. Use the arrows to follow how matter moves through this food web. For each answer choice, try to find a path of arrows to the bat star. The only arrow pointing from the sea otter leads to the orca. The only arrow pointing from the orca leads to the sea cucumber. No arrows point from the sea cucumber to any other organisms. So, in this food web, matter does not move from the sea otter to the bat star.There are three paths matter can take from the zooplankton to the bat star: zooplankton->kelp bass->bat star. zooplankton->plainfin midshipman->kelp bass->bat star. zooplankton->black rockfish->kelp bass->bat star. There is one path matter can take from the kelp to the bat star: kelp->kelp bass->bat star. orca. The only arrow pointing from the orca leads to the sea cucumber. No arrows point from the sea cucumber to any other organisms. So, in this food web, matter does not move from the orca to the bat star..

kelp

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Which animal is also adapted to be camouflaged in a sandy desert?

natural science

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The color, texture, and covering of an animal's skin are examples of adaptations. Animals' skins can be adapted in different ways. For example, skin with thick fur might help an animal stay warm. Skin with sharp spines might help an animal defend itself against predators.

Look at the picture of the camel. The camel has sand-colored fur covering its skin. It is adapted to be camouflaged in a sandy desert. The word camouflage means to blend in. Now look at each animal. Figure out which animal has a similar adaptation. The horned viper has sand-colored scales covering its body. It is adapted to be camouflaged in a sandy desert. This kingsnake has red, black, and yellow rings on its body. It is not adapted to be camouflaged in a sandy desert.

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The color, texture, and covering of an animal's skin are examples of adaptations. Animals' skins can be adapted in different ways. For example, skin with thick fur might help an animal stay warm. Skin with sharp spines might help an animal defend itself against predators. Look at the picture of the camel. The camel has sand-colored fur covering its skin. It is adapted to be camouflaged in a sandy desert. The word camouflage means to blend in. Now look at each animal. Figure out which animal has a similar adaptation. The horned viper has sand-colored scales covering its body. It is adapted to be camouflaged in a sandy desert. This kingsnake has red, black, and yellow rings on its body. It is not adapted to be camouflaged in a sandy desert.

horned viper

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Which is this organism's common name?

natural science

An organism's common name is the name that people normally call the organism. Common names often contain words you know. An organism's scientific name is the name scientists use to identify the organism. Scientific names often contain words that are not used in everyday English. Scientific names are written in italics, but common names are usually not. The first word of the scientific name is capitalized, and the second word is not. For example, the common name of the animal below is giant panda. Its scientific name is Ailuropoda melanoleuca.

Ceratophrys cornuta is written in italics. The first word is capitalized, and the second word is not. So, it is the scientific name. Ceratophrys cornuta is the organism's scientific name. So, you know that Surinam horned frog is the common name.

An organism's common name is the name that people normally call the organism. Common names often contain words you know. An organism's scientific name is the name scientists use to identify the organism. Scientific names often contain words that are not used in everyday English. Scientific names are written in italics, but common names are usually not. The first word of the scientific name is capitalized, and the second word is not. For example, the common name of the animal below is giant panda. Its scientific name is Ailuropoda melanoleuca. Ceratophrys cornuta is written in italics. The first word is capitalized, and the second word is not. So, it is the scientific name. Ceratophrys cornuta is the organism's scientific name. So, you know that Surinam horned frog is the common name.

Surinam horned frog

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What is this horse fly's scientific name?

natural science

When a scientist identifies a new organism, he or she chooses its scientific name. Sometimes, an organism is named after the place where it was first found. Other times, an organism is named after the scientist who first identified it. Or, the scientific name might describe the organism's physical traits. Many of the words that make up scientific names are based on words from old languages, like Latin and classical Greek. Sometimes, English words are changed to make them sound more like Latin or Greek. The new words are then used in an organism's scientific name.

This organism's scientific name refers to Beyoncé Knowles-Carter. The word beyonceae refers to Beyoncé Knowles-Carter. So, this horse fly's scientific name is Scaptia beyonceae.

When a scientist identifies a new organism, he or she chooses its scientific name. Sometimes, an organism is named after the place where it was first found. Other times, an organism is named after the scientist who first identified it. Or, the scientific name might describe the organism's physical traits. Many of the words that make up scientific names are based on words from old languages, like Latin and classical Greek. Sometimes, English words are changed to make them sound more like Latin or Greek. The new words are then used in an organism's scientific name. This organism's scientific name refers to Beyoncé Knowles-Carter. The word beyonceae refers to Beyoncé Knowles-Carter. So, this horse fly's scientific name is Scaptia beyonceae.

Scaptia beyonceae

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Does Rafflesia arnoldii have cells that have a nucleus?

natural science

In the past, scientists classified living organisms into two groups: plants and animals. Over the past 300 years, scientists have discovered many more types of organisms. Today, many scientists classify organisms into six broad groups, called kingdoms. Organisms in each kingdom have specific traits. The table below shows some traits used to describe each kingdom. | Bacteria | Archaea | Protists | Fungi | Animals | Plants How many cells do they have? | one | one | one or many | one or many | many | many Do their cells have a nucleus? | no | no | yes | yes | yes | yes Can their cells make food? | some species can | some species can | some species can | no | no | yes

Rafflesia arnoldii is a plant. Plant cells have a nucleus.

In the past, scientists classified living organisms into two groups: plants and animals. Over the past 300 years, scientists have discovered many more types of organisms. Today, many scientists classify organisms into six broad groups, called kingdoms. Organisms in each kingdom have specific traits. The table below shows some traits used to describe each kingdom. | Bacteria | Archaea | Protists | Fungi | Animals | Plants How many cells do they have? | one | one | one or many | one or many | many | many Do their cells have a nucleus? | no | no | yes | yes | yes | yes Can their cells make food? | some species can | some species can | some species can | no | no | yes Rafflesia arnoldii is a plant. Plant cells have a nucleus.

yes

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Does this passage describe the weather or the climate?

natural science

The atmosphere is the layer of air that surrounds Earth. Both weather and climate tell you about the atmosphere. Weather is what the atmosphere is like at a certain place and time. Weather can change quickly. For example, the temperature outside your house might get higher throughout the day. Climate is the pattern of weather in a certain place. For example, summer temperatures in New York are usually higher than winter temperatures.

Read the passage carefully. Houston is a city near the coast of Texas. On average, Houston receives about 49 inches of rain each year. The underlined part of the passage tells you about the usual pattern of precipitation in Houston. This passage does not describe what the weather is like on a particular day. So, this passage describes the climate.

The atmosphere is the layer of air that surrounds Earth. Both weather and climate tell you about the atmosphere. Weather is what the atmosphere is like at a certain place and time. Weather can change quickly. For example, the temperature outside your house might get higher throughout the day. Climate is the pattern of weather in a certain place. For example, summer temperatures in New York are usually higher than winter temperatures. Read the passage carefully. Houston is a city near the coast of Texas. On average, Houston receives about 49 inches of rain each year. The underlined part of the passage tells you about the usual pattern of precipitation in Houston. This passage does not describe what the weather is like on a particular day. So, this passage describes the climate.

climate

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What is the expected ratio of offspring with black wool to offspring with white wool? Choose the most likely ratio.

natural science

Offspring phenotypes: dominant or recessive? How do you determine an organism's phenotype for a trait? Look at the combination of alleles in the organism's genotype for the gene that affects that trait. Some alleles have types called dominant and recessive. These two types can cause different versions of the trait to appear as the organism's phenotype. If an organism's genotype has at least one dominant allele for a gene, the organism's phenotype will be the dominant allele's version of the gene's trait. If an organism's genotype has only recessive alleles for a gene, the organism's phenotype will be the recessive allele's version of the gene's trait. A Punnett square shows what types of offspring a cross can produce. The expected ratio of offspring types compares how often the cross produces each type of offspring, on average. To write this ratio, count the number of boxes in the Punnett square representing each type. For example, consider the Punnett square below. | F | f F | FF | Ff f | Ff | ff There is 1 box with the genotype FF and 2 boxes with the genotype Ff. So, the expected ratio of offspring with the genotype FF to those with Ff is 1:2.

To determine how many boxes in the Punnett square represent offspring with black wool or white wool, consider whether each phenotype is the dominant or recessive allele's version of the wool color trait. The question tells you that the L allele, which is for white wool, is dominant over the l allele, which is for black wool. Black wool is the recessive allele's version of the wool color trait. A sheep with the recessive version of the wool color trait must have only recessive alleles for the wool color gene. So, offspring with black wool must have the genotype ll. All 4 boxes in the Punnett square have the genotype ll. White wool is the dominant allele's version of the wool color trait. A sheep with the dominant version of the wool color trait must have at least one dominant allele for the wool color gene. So, offspring with white wool must have the genotype LL or Ll. There are 0 boxes in the Punnett square with the genotype LL or Ll. So, the expected ratio of offspring with black wool to offspring with white wool is 4:0. This means that, based on the Punnett square, this cross will always produce offspring with black wool. This cross is expected to never produce offspring with white wool.

Offspring phenotypes: dominant or recessive? How do you determine an organism's phenotype for a trait? Look at the combination of alleles in the organism's genotype for the gene that affects that trait. Some alleles have types called dominant and recessive. These two types can cause different versions of the trait to appear as the organism's phenotype. If an organism's genotype has at least one dominant allele for a gene, the organism's phenotype will be the dominant allele's version of the gene's trait. If an organism's genotype has only recessive alleles for a gene, the organism's phenotype will be the recessive allele's version of the gene's trait. A Punnett square shows what types of offspring a cross can produce. The expected ratio of offspring types compares how often the cross produces each type of offspring, on average. To write this ratio, count the number of boxes in the Punnett square representing each type. For example, consider the Punnett square below. | F | f F | FF | Ff f | Ff | ff There is 1 box with the genotype FF and 2 boxes with the genotype Ff. So, the expected ratio of offspring with the genotype FF to those with Ff is 1:2. To determine how many boxes in the Punnett square represent offspring with black wool or white wool, consider whether each phenotype is the dominant or recessive allele's version of the wool color trait. The question tells you that the L allele, which is for white wool, is dominant over the l allele, which is for black wool. Black wool is the recessive allele's version of the wool color trait. A sheep with the recessive version of the wool color trait must have only recessive alleles for the wool color gene. So, offspring with black wool must have the genotype ll. All 4 boxes in the Punnett square have the genotype ll. White wool is the dominant allele's version of the wool color trait. A sheep with the dominant version of the wool color trait must have at least one dominant allele for the wool color gene. So, offspring with white wool must have the genotype LL or Ll. There are 0 boxes in the Punnett square with the genotype LL or Ll. So, the expected ratio of offspring with black wool to offspring with white wool is 4:0. This means that, based on the Punnett square, this cross will always produce offspring with black wool. This cross is expected to never produce offspring with white wool.

4:0

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Which property do these two objects have in common?

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Different objects can have the same properties. You can use these properties to put objects into groups.

Look at each object. For each object, decide if it has that property. A soft object changes shape when you squeeze it. Both objects are soft. A bouncy object will bounce back from the floor if you drop it. The ball of wet clay is not bouncy. The property that both objects have in common is soft.

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Different objects can have the same properties. You can use these properties to put objects into groups. Look at each object. For each object, decide if it has that property. A soft object changes shape when you squeeze it. Both objects are soft. A bouncy object will bounce back from the floor if you drop it. The ball of wet clay is not bouncy. The property that both objects have in common is soft.

soft

619e257febc34cb88fcf2ba58ba93905

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Which solution has a higher concentration of blue particles?

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent

In Solution A and Solution B, the blue particles represent the solute. To figure out which solution has a higher concentration of blue particles, look at both the number of blue particles and the volume of the solvent in each container. Use the concentration formula to find the number of blue particles per milliliter. Solution B has more blue particles per milliliter. So, Solution B has a higher concentration of blue particles.

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent In Solution A and Solution B, the blue particles represent the solute. To figure out which solution has a higher concentration of blue particles, look at both the number of blue particles and the volume of the solvent in each container. Use the concentration formula to find the number of blue particles per milliliter. Solution B has more blue particles per milliliter. So, Solution B has a higher concentration of blue particles.

Solution B

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Which animal's limbs are also adapted for swimming?

natural science

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. Arms, legs, flippers, and wings are different types of limbs. The type of limbs an animal has is an example of an adaptation. Animals' limbs can be adapted in different ways. For example, long legs might help an animal run fast. Flippers might help an animal swim. Wings might help an animal fly.

Look at the picture of the sea turtle. The sea turtle uses its flippers to push itself through water. The flippers can also help it change direction while swimming. Now look at each animal. Figure out which animal has a similar adaptation. The California sea lion has flippers. Its limbs are adapted for swimming. The flying fox has large wings and short legs. Its limbs are not adapted for swimming. The flying fox uses its limbs to fly and hang from trees.

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. Arms, legs, flippers, and wings are different types of limbs. The type of limbs an animal has is an example of an adaptation. Animals' limbs can be adapted in different ways. For example, long legs might help an animal run fast. Flippers might help an animal swim. Wings might help an animal fly. Look at the picture of the sea turtle. The sea turtle uses its flippers to push itself through water. The flippers can also help it change direction while swimming. Now look at each animal. Figure out which animal has a similar adaptation. The California sea lion has flippers. Its limbs are adapted for swimming. The flying fox has large wings and short legs. Its limbs are not adapted for swimming. The flying fox uses its limbs to fly and hang from trees.

California sea lion

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Is chocolate a mineral?

natural science

Properties are used to identify different substances. Minerals have the following properties: It is a solid. It is formed in nature. It is not made by organisms. It is a pure substance. It has a fixed crystal structure. If a substance has all five of these properties, then it is a mineral. Look closely at the last three properties: A mineral is not made by organisms. Organisms make their own body parts. For example, snails and clams make their shells. Because they are made by organisms, body parts cannot be minerals. Humans are organisms too. So, substances that humans make by hand or in factories cannot be minerals. A mineral is a pure substance. A pure substance is made of only one type of matter. All minerals are pure substances. A mineral has a fixed crystal structure. The crystal structure of a substance tells you how the atoms or molecules in the substance are arranged. Different types of minerals have different crystal structures, but all minerals have a fixed crystal structure. This means that the atoms or molecules in different pieces of the same type of mineral are always arranged the same way.

Chocolate does not have all the properties of a mineral. So, chocolate is not a mineral.

Properties are used to identify different substances. Minerals have the following properties: It is a solid. It is formed in nature. It is not made by organisms. It is a pure substance. It has a fixed crystal structure. If a substance has all five of these properties, then it is a mineral. Look closely at the last three properties: A mineral is not made by organisms. Organisms make their own body parts. For example, snails and clams make their shells. Because they are made by organisms, body parts cannot be minerals. Humans are organisms too. So, substances that humans make by hand or in factories cannot be minerals. A mineral is a pure substance. A pure substance is made of only one type of matter. All minerals are pure substances. A mineral has a fixed crystal structure. The crystal structure of a substance tells you how the atoms or molecules in the substance are arranged. Different types of minerals have different crystal structures, but all minerals have a fixed crystal structure. This means that the atoms or molecules in different pieces of the same type of mineral are always arranged the same way. Chocolate does not have all the properties of a mineral. So, chocolate is not a mineral.

no

b74c0d88bf504c8b9df89557cf97691d

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Compare the average kinetic energies of the particles in each sample. Which sample has the higher temperature?

natural science

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy.

Each particle in sample A has more mass than each particle in sample B. The particles in sample A also have a higher average speed than the particles in sample B. So, the particles in sample A have a higher average kinetic energy than the particles in sample B. Because the particles in sample A have the higher average kinetic energy, sample A must have the higher temperature.

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy. Each particle in sample A has more mass than each particle in sample B. The particles in sample A also have a higher average speed than the particles in sample B. So, the particles in sample A have a higher average kinetic energy than the particles in sample B. Because the particles in sample A have the higher average kinetic energy, sample A must have the higher temperature.

sample A

eeba546dafd14067a7c8db16b13c352c

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Select the mammal below.

natural science

Birds, mammals, fish, reptiles, and amphibians are groups of animals. Scientists sort animals into each group based on traits they have in common. This process is called classification. Classification helps scientists learn about how animals live. Classification also helps scientists compare similar animals.

A robin is a bird. It has feathers, two wings, and a beak. A robin is a songbird. It sings different songs at different times of the day. A catfish is a fish. It lives underwater. It has fins, not limbs. Unlike most other fish, catfish do not have scales! They have slimy skin. A green moray eel is a fish. It lives underwater. It has fins, not limbs. Eels are long and thin. They may have small fins. They look like snakes, but they are fish! A red kangaroo is a mammal. It has fur and feeds its young milk. Kangaroos hop to move around. They use their large tails for balance while hopping.

Birds, mammals, fish, reptiles, and amphibians are groups of animals. Scientists sort animals into each group based on traits they have in common. This process is called classification. Classification helps scientists learn about how animals live. Classification also helps scientists compare similar animals. A robin is a bird. It has feathers, two wings, and a beak. A robin is a songbird. It sings different songs at different times of the day. A catfish is a fish. It lives underwater. It has fins, not limbs. Unlike most other fish, catfish do not have scales! They have slimy skin. A green moray eel is a fish. It lives underwater. It has fins, not limbs. Eels are long and thin. They may have small fins. They look like snakes, but they are fish! A red kangaroo is a mammal. It has fur and feeds its young milk. Kangaroos hop to move around. They use their large tails for balance while hopping.

red kangaroo

c2eb10a17cb0462cb9526258a6a3b9ad

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Complete the statement. Propane is ().

natural science

All substances are made of one or more chemical elements, or types of atoms. Substances that are made of only one chemical element are elementary substances. Substances that are made of two or more chemical elements bonded together are compounds. Every chemical element is represented by its own symbol. For some elements, the symbol is one capital letter. For other elements, the symbol is one capital letter and one lowercase letter. For example, the symbol for the chemical element boron is B, and the symbol for the chemical element chlorine is Cl. Scientists can use models to represent molecules. A ball-and-stick model of a molecule is shown below. This model represents a molecule of the compound boron trichloride. In a ball-and-stick model, the balls represent atoms, and the sticks represent chemical bonds. Notice how each ball is labeled with a symbol for a chemical element. The ball represents one atom of that element.

Count the number of chemical elements represented in the model. Then, decide if propane is an elementary substance or a compound. In this model, each ball is labeled with C for carbon or H for hydrogen. So, the model shows you that propane is made of two chemical elements bonded together. Substances made of two or more chemical elements bonded together are compounds. So, propane is a compound.

All substances are made of one or more chemical elements, or types of atoms. Substances that are made of only one chemical element are elementary substances. Substances that are made of two or more chemical elements bonded together are compounds. Every chemical element is represented by its own symbol. For some elements, the symbol is one capital letter. For other elements, the symbol is one capital letter and one lowercase letter. For example, the symbol for the chemical element boron is B, and the symbol for the chemical element chlorine is Cl. Scientists can use models to represent molecules. A ball-and-stick model of a molecule is shown below. This model represents a molecule of the compound boron trichloride. In a ball-and-stick model, the balls represent atoms, and the sticks represent chemical bonds. Notice how each ball is labeled with a symbol for a chemical element. The ball represents one atom of that element. Count the number of chemical elements represented in the model. Then, decide if propane is an elementary substance or a compound. In this model, each ball is labeled with C for carbon or H for hydrogen. So, the model shows you that propane is made of two chemical elements bonded together. Substances made of two or more chemical elements bonded together are compounds. So, propane is a compound.

a compound

824f38a444a042ba90ccd1104115418c

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Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is greater when the magnets are larger.

The magnets in Pair 1 attract. The magnets in Pair 2 repel. But whether the magnets attract or repel affects only the direction of the magnetic force. It does not affect the magnitude of the magnetic force. Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The larger the magnets, the greater the magnitude of the magnetic force between them. Magnet A is the same size in both pairs. But Magnet B is larger in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is greater in Pair 2 than in Pair 1.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is greater when the magnets are larger. The magnets in Pair 1 attract. The magnets in Pair 2 repel. But whether the magnets attract or repel affects only the direction of the magnetic force. It does not affect the magnitude of the magnetic force. Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The larger the magnets, the greater the magnitude of the magnetic force between them. Magnet A is the same size in both pairs. But Magnet B is larger in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is greater in Pair 2 than in Pair 1.

The magnitude of the magnetic force is greater in Pair 2.

04f662ef76f44eafa085866d597b5232

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Which of the following organisms is the omnivore in this food web?

natural science

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web.

Omnivores are consumers that eat both producers and other consumers. So, an omnivore has arrows pointing to it from at least one producer and at least one consumer. The black crappie has three arrows pointing to it. These arrows start from the rotifer, the water flea, and the shiner, which are all consumers. So, the black crappie is a consumer but not an omnivore. The rotifer has an arrow pointing to it from the green algae, which is a producer. The rotifer also has an arrow pointing to it from the water flea, which is a consumer. The rotifer eats a producer and a consumer, so it is an omnivore. The copepod has an arrow pointing to it from the golden algae, which is a producer. The copepod also has an arrow pointing to it from the rotifer, which is a consumer. The copepod eats a producer and a consumer, so it is an omnivore. The shiner has only one arrow pointing to it. This arrow starts from the water flea, which is a consumer. So, the shiner is a consumer but not an omnivore.

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web. Omnivores are consumers that eat both producers and other consumers. So, an omnivore has arrows pointing to it from at least one producer and at least one consumer. The black crappie has three arrows pointing to it. These arrows start from the rotifer, the water flea, and the shiner, which are all consumers. So, the black crappie is a consumer but not an omnivore. The rotifer has an arrow pointing to it from the green algae, which is a producer. The rotifer also has an arrow pointing to it from the water flea, which is a consumer. The rotifer eats a producer and a consumer, so it is an omnivore. The copepod has an arrow pointing to it from the golden algae, which is a producer. The copepod also has an arrow pointing to it from the rotifer, which is a consumer. The copepod eats a producer and a consumer, so it is an omnivore. The shiner has only one arrow pointing to it. This arrow starts from the water flea, which is a consumer. So, the shiner is a consumer but not an omnivore.

copepod

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Which property do these four objects have in common?

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification.

Look at each object. For each object, decide if it has that property. Sugar has a sweet taste. The trombone is not sweet. A shiny object reflects a lot of light. You can usually see your reflection in a shiny object. All four objects are shiny. You can see clearly through a transparent object. None of the objects are transparent. The property that all four objects have in common is shiny.

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification. Look at each object. For each object, decide if it has that property. Sugar has a sweet taste. The trombone is not sweet. A shiny object reflects a lot of light. You can usually see your reflection in a shiny object. All four objects are shiny. You can see clearly through a transparent object. None of the objects are transparent. The property that all four objects have in common is shiny.

shiny

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Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is smaller when the magnets are smaller.

Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The smaller the magnets, the smaller the magnitude of the magnetic force between them. Magnet A is the same size in both pairs. But Magnet B is smaller in Pair 1 than in Pair 2. So, the magnitude of the magnetic force is smaller in Pair 1 than in Pair 2.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by using magnets of different sizes. The magnitude of the magnetic force is smaller when the magnets are smaller. Magnet sizes affect the magnitude of the magnetic force. Imagine magnets that are the same shape and made of the same material. The smaller the magnets, the smaller the magnitude of the magnetic force between them. Magnet A is the same size in both pairs. But Magnet B is smaller in Pair 1 than in Pair 2. So, the magnitude of the magnetic force is smaller in Pair 1 than in Pair 2.

The magnitude of the magnetic force is smaller in Pair 1.

48037cd6038f4ab6b732b239b00d9ff6

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Which solution has a higher concentration of purple particles?

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent

In Solution A and Solution B, the purple particles represent the solute. To figure out which solution has a higher concentration of purple particles, look at both the number of purple particles and the volume of the solvent in each container. Use the concentration formula to find the number of purple particles per milliliter. Solution B has more purple particles per milliliter. So, Solution B has a higher concentration of purple particles.

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent In Solution A and Solution B, the purple particles represent the solute. To figure out which solution has a higher concentration of purple particles, look at both the number of purple particles and the volume of the solvent in each container. Use the concentration formula to find the number of purple particles per milliliter. Solution B has more purple particles per milliliter. So, Solution B has a higher concentration of purple particles.

Solution B

0c0c47b7fbe24ca8aa3854c39a7cf278

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Which of these oceans does the prime meridian intersect?

social science

Lines of latitude and lines of longitude are imaginary lines drawn on some globes and maps. They can help you find places on globes and maps. Lines of latitude show how far north or south a place is. We use units called degrees to describe how far a place is from the equator. The equator is the line located at 0° latitude. We start counting degrees from there. Lines north of the equator are labeled N for north. Lines south of the equator are labeled S for south. Lines of latitude are also called parallels because each line is parallel to the equator. Lines of longitude are also called meridians. They show how far east or west a place is. We use degrees to help describe how far a place is from the prime meridian. The prime meridian is the line located at 0° longitude. Lines west of the prime meridian are labeled W. Lines east of the prime meridian are labeled E. Meridians meet at the north and south poles. The equator goes all the way around the earth, but the prime meridian is different. It only goes from the North Pole to the South Pole on one side of the earth. On the opposite side of the globe is another special meridian. It is labeled both 180°E and 180°W. Together, lines of latitude and lines of longitude form a grid. You can use this grid to find the exact location of a place.

The prime meridian is the line at 0° longitude. It intersects the Atlantic Ocean. It does not intersect the Indian Ocean or the Pacific Ocean.

Lines of latitude and lines of longitude are imaginary lines drawn on some globes and maps. They can help you find places on globes and maps. Lines of latitude show how far north or south a place is. We use units called degrees to describe how far a place is from the equator. The equator is the line located at 0° latitude. We start counting degrees from there. Lines north of the equator are labeled N for north. Lines south of the equator are labeled S for south. Lines of latitude are also called parallels because each line is parallel to the equator. Lines of longitude are also called meridians. They show how far east or west a place is. We use degrees to help describe how far a place is from the prime meridian. The prime meridian is the line located at 0° longitude. Lines west of the prime meridian are labeled W. Lines east of the prime meridian are labeled E. Meridians meet at the north and south poles. The equator goes all the way around the earth, but the prime meridian is different. It only goes from the North Pole to the South Pole on one side of the earth. On the opposite side of the globe is another special meridian. It is labeled both 180°E and 180°W. Together, lines of latitude and lines of longitude form a grid. You can use this grid to find the exact location of a place. The prime meridian is the line at 0° longitude. It intersects the Atlantic Ocean. It does not intersect the Indian Ocean or the Pacific Ocean.

the Atlantic Ocean

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Which of these states is farthest south?

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.

To find the answer, look at the compass rose. Look at which way the south arrow is pointing. Kansas is farthest south.

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map. To find the answer, look at the compass rose. Look at which way the south arrow is pointing. Kansas is farthest south.

Kansas

283f84887ecb445ea43443a1762c6cf5

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Which solution has a higher concentration of green particles?

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent

In Solution A and Solution B, the green particles represent the solute. To figure out which solution has a higher concentration of green particles, look at both the number of green particles and the volume of the solvent in each container. Use the concentration formula to find the number of green particles per milliliter. Solution A has more green particles per milliliter. So, Solution A has a higher concentration of green particles.

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent In Solution A and Solution B, the green particles represent the solute. To figure out which solution has a higher concentration of green particles, look at both the number of green particles and the volume of the solvent in each container. Use the concentration formula to find the number of green particles per milliliter. Solution A has more green particles per milliliter. So, Solution A has a higher concentration of green particles.

Solution A

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Look at the picture. Which word best describes the sound this hammer makes?

language science

When you write, you can use sensory details. These sense words help your reader understand what something looks, sounds, tastes, smells, or feels like. Sensory Category | Description Sight | These are words like bright, clean, and purple. A reader can imagine looking at these details. Sound | These are words like hissing, buzzing, and ringing. A reader can imagine hearing these details. Taste | These are words like juicy, sweet, and burnt. A reader can imagine tasting these details. Smell | These are words like fruity, sweet, and stinky. A reader can imagine smelling these details. Touch | These are words like fuzzy, wet, and soft. A reader can imagine feeling these details. Many sense words can describe more than one sense. For example, soft can describe a touch or a sound. And sweet can describe a taste or a smell.

Look at the picture. The word banging describes the sound this hammer makes. Dripping and buzzing can also describe sounds. But they do not describe the sounds this hammer makes.

When you write, you can use sensory details. These sense words help your reader understand what something looks, sounds, tastes, smells, or feels like. Sensory Category | Description Sight | These are words like bright, clean, and purple. A reader can imagine looking at these details. Sound | These are words like hissing, buzzing, and ringing. A reader can imagine hearing these details. Taste | These are words like juicy, sweet, and burnt. A reader can imagine tasting these details. Smell | These are words like fruity, sweet, and stinky. A reader can imagine smelling these details. Touch | These are words like fuzzy, wet, and soft. A reader can imagine feeling these details. Many sense words can describe more than one sense. For example, soft can describe a touch or a sound. And sweet can describe a taste or a smell. Look at the picture. The word banging describes the sound this hammer makes. Dripping and buzzing can also describe sounds. But they do not describe the sounds this hammer makes.

banging

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Will these magnets attract or repel each other?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles: north and south. Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

To predict if these magnets will attract or repel, look at which poles are closest to each other. The south pole of one magnet is closest to the south pole of the other magnet. Like poles repel. So, these magnets will repel each other.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles: north and south. Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel. To predict if these magnets will attract or repel, look at which poles are closest to each other. The south pole of one magnet is closest to the south pole of the other magnet. Like poles repel. So, these magnets will repel each other.

repel

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Complete the statement. Lithium bromide is ().

natural science

There are more than 100 different chemical elements, or types of atoms. Chemical elements make up all of the substances around you. A substance may be composed of one chemical element or multiple chemical elements. Substances that are composed of only one chemical element are elementary substances. Substances that are composed of multiple chemical elements bonded together are compounds. Every chemical element is represented by its own atomic symbol. An atomic symbol may consist of one capital letter, or it may consist of a capital letter followed by a lowercase letter. For example, the atomic symbol for the chemical element fluorine is F, and the atomic symbol for the chemical element beryllium is Be. Scientists use different types of models to represent substances whose atoms are bonded in different ways. One type of model is a space-filling model. The space-filling model below represents the compound potassium chloride. In a space-filling model, the balls represent atoms that are bonded together. Notice that the balls in the model above are not all the same color. Each color represents a different chemical element. The legend shows the color and the atomic symbol for each chemical element in the substance.

Use the model to determine whether lithium bromide is an elementary substance or a compound. Step 1: Interpret the model. . Use the legend to determine the chemical element represented by each color. The colors and atomic symbols from the legend are shown in the table below. The table also includes the names of the chemical elements represented in the model. You can see from the model that lithium bromide is composed of lithium atoms and bromine atoms bonded together. Step 2: Determine whether the substance is an elementary substance or a compound. You know from Step 1 that lithium bromide is composed of two chemical elements: lithium and bromine. Since lithium bromide is composed of multiple chemical elements bonded together, lithium bromide is a compound.

There are more than 100 different chemical elements, or types of atoms. Chemical elements make up all of the substances around you. A substance may be composed of one chemical element or multiple chemical elements. Substances that are composed of only one chemical element are elementary substances. Substances that are composed of multiple chemical elements bonded together are compounds. Every chemical element is represented by its own atomic symbol. An atomic symbol may consist of one capital letter, or it may consist of a capital letter followed by a lowercase letter. For example, the atomic symbol for the chemical element fluorine is F, and the atomic symbol for the chemical element beryllium is Be. Scientists use different types of models to represent substances whose atoms are bonded in different ways. One type of model is a space-filling model. The space-filling model below represents the compound potassium chloride. In a space-filling model, the balls represent atoms that are bonded together. Notice that the balls in the model above are not all the same color. Each color represents a different chemical element. The legend shows the color and the atomic symbol for each chemical element in the substance. Use the model to determine whether lithium bromide is an elementary substance or a compound. Step 1: Interpret the model. . Use the legend to determine the chemical element represented by each color. The colors and atomic symbols from the legend are shown in the table below. The table also includes the names of the chemical elements represented in the model. You can see from the model that lithium bromide is composed of lithium atoms and bromine atoms bonded together. Step 2: Determine whether the substance is an elementary substance or a compound. You know from Step 1 that lithium bromide is composed of two chemical elements: lithium and bromine. Since lithium bromide is composed of multiple chemical elements bonded together, lithium bromide is a compound.

a compound

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Which solution has a higher concentration of pink particles?

natural science

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent

In Solution A and Solution B, the pink particles represent the solute. To figure out which solution has a higher concentration of pink particles, look at both the number of pink particles and the volume of the solvent in each container. Use the concentration formula to find the number of pink particles per milliliter. Solution B has more pink particles per milliliter. So, Solution B has a higher concentration of pink particles.

A solution is made up of two or more substances that are completely mixed. In a solution, solute particles are mixed into a solvent. The solute cannot be separated from the solvent by a filter. For example, if you stir a spoonful of salt into a cup of water, the salt will mix into the water to make a saltwater solution. In this case, the salt is the solute. The water is the solvent. The concentration of a solute in a solution is a measure of the ratio of solute to solvent. Concentration can be described in terms of particles of solute per volume of solvent. concentration = particles of solute / volume of solvent In Solution A and Solution B, the pink particles represent the solute. To figure out which solution has a higher concentration of pink particles, look at both the number of pink particles and the volume of the solvent in each container. Use the concentration formula to find the number of pink particles per milliliter. Solution B has more pink particles per milliliter. So, Solution B has a higher concentration of pink particles.

Solution B

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Will these magnets attract or repel each other?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles: north and south. Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

To predict if these magnets will attract or repel, look at which poles are closest to each other. The north pole of one magnet is closest to the north pole of the other magnet. Like poles repel. So, these magnets will repel each other.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. Whether a magnet attracts or repels other magnets depends on the positions of its poles, or ends. Every magnet has two poles: north and south. Here are some examples of magnets. The north pole of each magnet is labeled N, and the south pole is labeled S. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel. To predict if these magnets will attract or repel, look at which poles are closest to each other. The north pole of one magnet is closest to the north pole of the other magnet. Like poles repel. So, these magnets will repel each other.

repel

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Which animal's mouth is also adapted for gnawing?

natural science

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The shape of an animal's mouth is one example of an adaptation. Animals' mouths can be adapted in different ways. For example, a large mouth with sharp teeth might help an animal tear through meat. A long, thin mouth might help an animal catch insects that live in holes. Animals that eat similar food often have similar mouths.

Look at the picture of the nutria. The nutria has large front teeth. Its mouth is adapted for gnawing. The large front teeth can help the nutria break off pieces of food that it can swallow. Now look at each animal. Figure out which animal has a similar adaptation. The Podolsk mole rat has large front teeth. Its mouth is adapted for gnawing. The tamandua has a long tube-shaped mouth and no teeth. Its mouth is not adapted for gnawing. The tamandua uses its mouth to get insects out of holes and burrows.

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The shape of an animal's mouth is one example of an adaptation. Animals' mouths can be adapted in different ways. For example, a large mouth with sharp teeth might help an animal tear through meat. A long, thin mouth might help an animal catch insects that live in holes. Animals that eat similar food often have similar mouths. Look at the picture of the nutria. The nutria has large front teeth. Its mouth is adapted for gnawing. The large front teeth can help the nutria break off pieces of food that it can swallow. Now look at each animal. Figure out which animal has a similar adaptation. The Podolsk mole rat has large front teeth. Its mouth is adapted for gnawing. The tamandua has a long tube-shaped mouth and no teeth. Its mouth is not adapted for gnawing. The tamandua uses its mouth to get insects out of holes and burrows.

Podolsk mole rat

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What type of rock is marble?

natural science

Igneous rock is formed when melted rock cools and hardens into solid rock. This type of change can occur at Earth's surface or below it. Sedimentary rock is formed when layers of sediment are pressed together to make rock. This type of change occurs below Earth's surface. Metamorphic rock is formed when a rock is changed by heating and squeezing. This type of change often occurs deep below Earth's surface. Over time, the old rock becomes a new rock with different properties.

Marble is a metamorphic rock. Like other metamorphic rocks, it forms when a rock is changed by heating and squeezing. The center of our planet is very hot. Deep below Earth's surface, rocks can be heated to high temperatures. The rocks can also be squeezed by the weight of rocks around them. Sometimes, the heating and squeezing changes the type of minerals in a rock. These changes form a new type of rock, called a metamorphic rock. The word metamorphic comes from the word metamorphism, which means change.

Igneous rock is formed when melted rock cools and hardens into solid rock. This type of change can occur at Earth's surface or below it. Sedimentary rock is formed when layers of sediment are pressed together to make rock. This type of change occurs below Earth's surface. Metamorphic rock is formed when a rock is changed by heating and squeezing. This type of change often occurs deep below Earth's surface. Over time, the old rock becomes a new rock with different properties. Marble is a metamorphic rock. Like other metamorphic rocks, it forms when a rock is changed by heating and squeezing. The center of our planet is very hot. Deep below Earth's surface, rocks can be heated to high temperatures. The rocks can also be squeezed by the weight of rocks around them. Sometimes, the heating and squeezing changes the type of minerals in a rock. These changes form a new type of rock, called a metamorphic rock. The word metamorphic comes from the word metamorphism, which means change.

metamorphic

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Which statement is true about the average monthly precipitation in Charlotte?

natural science

Scientists record climate data from places around the world. Precipitation, or rain and snow, is one type of climate data. Scientists collect data over many years. They can use this data to calculate the average precipitation for each month. The average precipitation can be used to describe the climate of a location. A bar graph can be used to show the average amount of precipitation each month. Months with taller bars have more precipitation on average.

To describe the average precipitation trends in Charlotte, look at the graph. Choice "Jan" is incorrect. Choice "Jun" is incorrect. Choice "Jul" is incorrect. Choice "June is wetter than July." is incorrect. Wetter months have a higher average precipitation than drier months. June and July have the same average monthly precipitation. So, June is not wetter than July. Choice "January is the month with the highest average precipitation." is incorrect. Several other months have a slightly higher average precipitation than January. Choice "Precipitation does not change much from month to month." is incorrect. The average monthly precipitation changes only slightly throughout the year.

Scientists record climate data from places around the world. Precipitation, or rain and snow, is one type of climate data. Scientists collect data over many years. They can use this data to calculate the average precipitation for each month. The average precipitation can be used to describe the climate of a location. A bar graph can be used to show the average amount of precipitation each month. Months with taller bars have more precipitation on average. To describe the average precipitation trends in Charlotte, look at the graph. Choice "Jan" is incorrect. Choice "Jun" is incorrect. Choice "Jul" is incorrect. Choice "June is wetter than July." is incorrect. Wetter months have a higher average precipitation than drier months. June and July have the same average monthly precipitation. So, June is not wetter than July. Choice "January is the month with the highest average precipitation." is incorrect. Several other months have a slightly higher average precipitation than January. Choice "Precipitation does not change much from month to month." is incorrect. The average monthly precipitation changes only slightly throughout the year.

Precipitation does not change much from month to month.

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In this food web, which organism contains matter that eventually moves to the sea cucumber?

natural science

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web.

Use the arrows to follow how matter moves through this food web. For each answer choice, try to find a path of arrows to the sea cucumber.There is one path matter can take from the kelp to the sea cucumber: kelp->sea urchin->sea otter->orca->sea cucumber. black rockfish. The only arrow pointing from the black rockfish leads to the kelp bass. The only arrow pointing from the kelp bass leads to the bat star. No arrows point from the bat star to any other organisms. So, in this food web, matter does not move from the black rockfish to the sea cucumber.. kelp bass. The only arrow pointing from the kelp bass leads to the bat star. No arrows point from the bat star to any other organisms. So, in this food web, matter does not move from the kelp bass to the sea cucumber.. bat star. No arrows point from the bat star to any other organisms. So, in this food web, matter does not move from the bat star to the sea cucumber..

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web. Use the arrows to follow how matter moves through this food web. For each answer choice, try to find a path of arrows to the sea cucumber.There is one path matter can take from the kelp to the sea cucumber: kelp->sea urchin->sea otter->orca->sea cucumber. black rockfish. The only arrow pointing from the black rockfish leads to the kelp bass. The only arrow pointing from the kelp bass leads to the bat star. No arrows point from the bat star to any other organisms. So, in this food web, matter does not move from the black rockfish to the sea cucumber.. kelp bass. The only arrow pointing from the kelp bass leads to the bat star. No arrows point from the bat star to any other organisms. So, in this food web, matter does not move from the kelp bass to the sea cucumber.. bat star. No arrows point from the bat star to any other organisms. So, in this food web, matter does not move from the bat star to the sea cucumber..

kelp

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During this time, thermal energy was transferred from () to ().

natural science

A change in an object's temperature indicates a change in the object's thermal energy: An increase in temperature shows that the object's thermal energy increased. So, thermal energy was transferred into the object from its surroundings. A decrease in temperature shows that the object's thermal energy decreased. So, thermal energy was transferred out of the object to its surroundings.

The temperature of each salmon increased, which means that the thermal energy of each salmon increased. So, thermal energy was transferred from the surroundings to each salmon.

A change in an object's temperature indicates a change in the object's thermal energy: An increase in temperature shows that the object's thermal energy increased. So, thermal energy was transferred into the object from its surroundings. A decrease in temperature shows that the object's thermal energy decreased. So, thermal energy was transferred out of the object to its surroundings. The temperature of each salmon increased, which means that the thermal energy of each salmon increased. So, thermal energy was transferred from the surroundings to each salmon.

the surroundings . . . each salmon

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Select the organism in the same species as the Victoria crowned pigeon.

natural science

Scientists use scientific names to identify organisms. Scientific names are made of two words. The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits. A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus. Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus. Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur.

A Victoria crowned pigeon's scientific name is Goura victoria. Dendrobates leucomelas does not have the same scientific name as a Victoria crowned pigeon. So, Goura victoria and Dendrobates leucomelas are not in the same species. Aequorea victoria does have the same species within its genus as a Victoria crowned pigeon, but they are not in the same genus! They do not have the same scientific name as each other. So, these organisms are not in the same species. Goura victoria has the same scientific name as a Victoria crowned pigeon. So, these organisms are in the same species.

Scientists use scientific names to identify organisms. Scientific names are made of two words. The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits. A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus. Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus. Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur. A Victoria crowned pigeon's scientific name is Goura victoria. Dendrobates leucomelas does not have the same scientific name as a Victoria crowned pigeon. So, Goura victoria and Dendrobates leucomelas are not in the same species. Aequorea victoria does have the same species within its genus as a Victoria crowned pigeon, but they are not in the same genus! They do not have the same scientific name as each other. So, these organisms are not in the same species. Goura victoria has the same scientific name as a Victoria crowned pigeon. So, these organisms are in the same species.

Goura victoria

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Is syenite a mineral or a rock?

natural science

Minerals are the building blocks of rocks. A rock can be made of one or more minerals. Minerals and rocks have the following properties: Property | Mineral | Rock It is a solid. | Yes | Yes It is formed in nature. | Yes | Yes It is not made by organisms. | Yes | Yes It is a pure substance. | Yes | No It has a fixed crystal structure. | Yes | No You can use these properties to tell whether a substance is a mineral, a rock, or neither. Look closely at the last three properties: Minerals and rocks are not made by organisms. Organisms make their own body parts. For example, snails and clams make their shells. Because they are made by organisms, body parts cannot be minerals or rocks. Humans are organisms too. So, substances that humans make by hand or in factories are not minerals or rocks. A mineral is a pure substance, but a rock is not. A pure substance is made of only one type of matter. Minerals are pure substances, but rocks are not. Instead, all rocks are mixtures. A mineral has a fixed crystal structure, but a rock does not. The crystal structure of a substance tells you how the atoms or molecules in the substance are arranged. Different types of minerals have different crystal structures, but all minerals have a fixed crystal structure. This means that the atoms and molecules in different pieces of the same type of mineral are always arranged the same way. However, rocks do not have a fixed crystal structure. So, the arrangement of atoms or molecules in different pieces of the same type of rock may be different!

The properties of syenite match the properties of a rock. So, syenite is a rock.

Minerals are the building blocks of rocks. A rock can be made of one or more minerals. Minerals and rocks have the following properties: Property | Mineral | Rock It is a solid. | Yes | Yes It is formed in nature. | Yes | Yes It is not made by organisms. | Yes | Yes It is a pure substance. | Yes | No It has a fixed crystal structure. | Yes | No You can use these properties to tell whether a substance is a mineral, a rock, or neither. Look closely at the last three properties: Minerals and rocks are not made by organisms. Organisms make their own body parts. For example, snails and clams make their shells. Because they are made by organisms, body parts cannot be minerals or rocks. Humans are organisms too. So, substances that humans make by hand or in factories are not minerals or rocks. A mineral is a pure substance, but a rock is not. A pure substance is made of only one type of matter. Minerals are pure substances, but rocks are not. Instead, all rocks are mixtures. A mineral has a fixed crystal structure, but a rock does not. The crystal structure of a substance tells you how the atoms or molecules in the substance are arranged. Different types of minerals have different crystal structures, but all minerals have a fixed crystal structure. This means that the atoms and molecules in different pieces of the same type of mineral are always arranged the same way. However, rocks do not have a fixed crystal structure. So, the arrangement of atoms or molecules in different pieces of the same type of rock may be different! The properties of syenite match the properties of a rock. So, syenite is a rock.

rock

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In this food web, which organism contains matter that eventually moves to the parasol fungus?

natural science

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web.

Use the arrows to follow how matter moves through this food web. For each answer choice, try to find a path of arrows to the parasol fungus. There are two arrows pointing from the gray fox to other organisms. One arrow points to the bobcat. The only arrow pointing from the bobcat leads to the bolete fungus. The other arrow pointing from the gray fox leads to the bolete fungus. No arrows point from the bolete fungus to any other organisms. So, in this food web, matter does not move from the gray fox to the parasol fungus. The only arrow pointing from the black racer leads to the bolete fungus. No arrows point from the bolete fungus to any other organisms. So, in this food web, matter does not move from the black racer to the parasol fungus.There is one path matter can take from the black bear to the parasol fungus: black bear->parasol fungus. bobcat. The only arrow pointing from the bobcat leads to the bolete fungus. No arrows point from the bolete fungus to any other organisms. So, in this food web, matter does not move from the bobcat to the parasol fungus.. There is one path matter can take from the beaver to the parasol fungus: beaver->black bear->parasol fungus.

A food web is a model. A food web shows where organisms in an ecosystem get their food. Models can make things in nature easier to understand because models can represent complex things in a simpler way. If a food web showed every organism in an ecosystem, the food web would be hard to understand. So, each food web shows how some organisms in an ecosystem can get their food. Arrows show how matter moves. A food web has arrows that point from one organism to another. Each arrow shows the direction that matter moves when one organism eats another organism. An arrow starts from the organism that is eaten. The arrow points to the organism that is doing the eating. An organism in a food web can have more than one arrow pointing from it. This shows that the organism is eaten by more than one other organism in the food web. An organism in a food web can also have more than one arrow pointing to it. This shows that the organism eats more than one other organism in the food web. Use the arrows to follow how matter moves through this food web. For each answer choice, try to find a path of arrows to the parasol fungus. There are two arrows pointing from the gray fox to other organisms. One arrow points to the bobcat. The only arrow pointing from the bobcat leads to the bolete fungus. The other arrow pointing from the gray fox leads to the bolete fungus. No arrows point from the bolete fungus to any other organisms. So, in this food web, matter does not move from the gray fox to the parasol fungus. The only arrow pointing from the black racer leads to the bolete fungus. No arrows point from the bolete fungus to any other organisms. So, in this food web, matter does not move from the black racer to the parasol fungus.There is one path matter can take from the black bear to the parasol fungus: black bear->parasol fungus. bobcat. The only arrow pointing from the bobcat leads to the bolete fungus. No arrows point from the bolete fungus to any other organisms. So, in this food web, matter does not move from the bobcat to the parasol fungus.. There is one path matter can take from the beaver to the parasol fungus: beaver->black bear->parasol fungus.

beaver

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Is an empty glass a solid, a liquid, or a gas?

natural science

Solid, liquid, and gas are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms. When matter is a solid, it has a definite volume and a definite shape. So, a solid has a size and shape of its own. Some solids can be easily folded, bent, or broken. A piece of paper is a solid. Also, some solids are very small. A grain of sand is a solid. When matter is a liquid, it has a definite volume but not a definite shape. So, a liquid has a size of its own, but it does not have a shape of its own. Think about pouring juice from a bottle into a cup. The juice still takes up the same amount of space, but it takes the shape of the bottle. Some liquids do not pour as easily as others. Honey and milk are both liquids. But pouring honey takes more time than pouring milk. When matter is a gas, it does not have a definite volume or a definite shape. A gas expands, or gets bigger, until it completely fills a space. A gas can also get smaller if it is squeezed into a smaller space. Many gases are invisible. Air is a gas.

An empty glass is a solid. If someone drops a glass, it may break into pieces. But each piece will still have a size and shape of its own.

Solid, liquid, and gas are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms. When matter is a solid, it has a definite volume and a definite shape. So, a solid has a size and shape of its own. Some solids can be easily folded, bent, or broken. A piece of paper is a solid. Also, some solids are very small. A grain of sand is a solid. When matter is a liquid, it has a definite volume but not a definite shape. So, a liquid has a size of its own, but it does not have a shape of its own. Think about pouring juice from a bottle into a cup. The juice still takes up the same amount of space, but it takes the shape of the bottle. Some liquids do not pour as easily as others. Honey and milk are both liquids. But pouring honey takes more time than pouring milk. When matter is a gas, it does not have a definite volume or a definite shape. A gas expands, or gets bigger, until it completely fills a space. A gas can also get smaller if it is squeezed into a smaller space. Many gases are invisible. Air is a gas. An empty glass is a solid. If someone drops a glass, it may break into pieces. But each piece will still have a size and shape of its own.

a solid

d70b287cc30c4388b08e0fde008f83ad

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Is Lithops bromfieldii made up of one cell?

natural science

In the past, scientists classified living organisms into two groups: plants and animals. Over the past 300 years, scientists have discovered many more types of organisms. Today, many scientists classify organisms into six broad groups, called kingdoms. Organisms in each kingdom have specific traits. The table below shows some traits used to describe each kingdom. | Bacteria | Archaea | Protists | Fungi | Animals | Plants How many cells do they have? | one | one | one or many | one or many | many | many Do their cells have a nucleus? | no | no | yes | yes | yes | yes Can their cells make food? | some species can | some species can | some species can | no | no | yes

Lithops bromfieldii is a plant. Plants are made up of many cells.

In the past, scientists classified living organisms into two groups: plants and animals. Over the past 300 years, scientists have discovered many more types of organisms. Today, many scientists classify organisms into six broad groups, called kingdoms. Organisms in each kingdom have specific traits. The table below shows some traits used to describe each kingdom. | Bacteria | Archaea | Protists | Fungi | Animals | Plants How many cells do they have? | one | one | one or many | one or many | many | many Do their cells have a nucleus? | no | no | yes | yes | yes | yes Can their cells make food? | some species can | some species can | some species can | no | no | yes Lithops bromfieldii is a plant. Plants are made up of many cells.

no

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Which of these states is farthest north?

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.

To find the answer, look at the compass rose. Look at which way the north arrow is pointing. Vermont is farthest north.

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map. To find the answer, look at the compass rose. Look at which way the north arrow is pointing. Vermont is farthest north.

Vermont

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Compare the average kinetic energies of the particles in each sample. Which sample has the higher temperature?

natural science

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy.

The particles in both samples have the same average speed, but each particle in sample A has more mass than each particle in sample B. So, the particles in sample A have a higher average kinetic energy than the particles in sample B. Because the particles in sample A have the higher average kinetic energy, sample A must have the higher temperature.

The temperature of a substance depends on the average kinetic energy of the particles in the substance. The higher the average kinetic energy of the particles, the higher the temperature of the substance. The kinetic energy of a particle is determined by its mass and speed. For a pure substance, the greater the mass of each particle in the substance and the higher the average speed of the particles, the higher their average kinetic energy. The particles in both samples have the same average speed, but each particle in sample A has more mass than each particle in sample B. So, the particles in sample A have a higher average kinetic energy than the particles in sample B. Because the particles in sample A have the higher average kinetic energy, sample A must have the higher temperature.

sample A

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Will these magnets attract or repel each other?

natural science

Magnets can pull or push on other magnets without touching them. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes are called magnetic forces. Magnetic forces are strongest at the magnets' poles, or ends. Every magnet has two poles: a north pole (N) and a south pole (S). Here are some examples of magnets. Their poles are shown in different colors and labeled. Whether a magnet attracts or repels other magnets depends on the positions of its poles. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel.

To predict if these magnets will attract or repel, look at which poles are closest to each other. The south pole of one magnet is closest to the south pole of the other magnet. Like poles repel. So, these magnets will repel each other.

Magnets can pull or push on other magnets without touching them. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes are called magnetic forces. Magnetic forces are strongest at the magnets' poles, or ends. Every magnet has two poles: a north pole (N) and a south pole (S). Here are some examples of magnets. Their poles are shown in different colors and labeled. Whether a magnet attracts or repels other magnets depends on the positions of its poles. If opposite poles are closest to each other, the magnets attract. The magnets in the pair below attract. If the same, or like, poles are closest to each other, the magnets repel. The magnets in both pairs below repel. To predict if these magnets will attract or repel, look at which poles are closest to each other. The south pole of one magnet is closest to the south pole of the other magnet. Like poles repel. So, these magnets will repel each other.

repel

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Which of these states is farthest west?

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.

To find the answer, look at the compass rose. Look at which way the west arrow is pointing. Louisiana is farthest west.

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map. To find the answer, look at the compass rose. Look at which way the west arrow is pointing. Louisiana is farthest west.

Louisiana

25908dfe6cc84f4ea3d1b36043298e79

validation_images/image_188.png

Is a watch a solid, a liquid, or a gas?

natural science

Solid, liquid, and gas are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms. When matter is a solid, it has a definite volume and a definite shape. So, a solid has a size and shape of its own. Some solids can be easily folded, bent, or broken. A piece of paper is a solid. Also, some solids are very small. A grain of sand is a solid. When matter is a liquid, it has a definite volume but not a definite shape. So, a liquid has a size of its own, but it does not have a shape of its own. Think about pouring juice from a bottle into a cup. The juice still takes up the same amount of space, but it takes the shape of the bottle. Some liquids are thicker than others. Honey and milk are both liquids. But pouring honey takes more time than pouring milk. When matter is a gas, it does not have a definite volume or a definite shape. A gas expands, or gets bigger, until it completely fills a space. A gas can also get smaller if it is squeezed into a smaller space. Many gases are invisible. The oxygen you breathe is a gas. The helium in a balloon is also a gas.

A watch is a solid. A solid has a size and shape of its own. A watch can bend to fit your wrist, but the watch will still have its own shape.

Solid, liquid, and gas are states of matter. Matter is anything that takes up space. Matter can come in different states, or forms. When matter is a solid, it has a definite volume and a definite shape. So, a solid has a size and shape of its own. Some solids can be easily folded, bent, or broken. A piece of paper is a solid. Also, some solids are very small. A grain of sand is a solid. When matter is a liquid, it has a definite volume but not a definite shape. So, a liquid has a size of its own, but it does not have a shape of its own. Think about pouring juice from a bottle into a cup. The juice still takes up the same amount of space, but it takes the shape of the bottle. Some liquids are thicker than others. Honey and milk are both liquids. But pouring honey takes more time than pouring milk. When matter is a gas, it does not have a definite volume or a definite shape. A gas expands, or gets bigger, until it completely fills a space. A gas can also get smaller if it is squeezed into a smaller space. Many gases are invisible. The oxygen you breathe is a gas. The helium in a balloon is also a gas. A watch is a solid. A solid has a size and shape of its own. A watch can bend to fit your wrist, but the watch will still have its own shape.

a solid

5e8f5e9b551843f6b70bed4fc8865a6f

validation_images/image_189.png

Which of these states is farthest east?

social science

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map.

To find the answer, look at the compass rose. Look at which way the east arrow is pointing. Kentucky is farthest east.

Maps have four cardinal directions, or main directions. Those directions are north, south, east, and west. A compass rose is a set of arrows that point to the cardinal directions. A compass rose usually shows only the first letter of each cardinal direction. The north arrow points to the North Pole. On most maps, north is at the top of the map. To find the answer, look at the compass rose. Look at which way the east arrow is pointing. Kentucky is farthest east.

Kentucky

6a22d216944d4b12846f63227e18ff3d

validation_images/image_190.png

In this experiment, which were part of a control group?

natural science

Experiments have variables, or parts that change. You can design an experiment to investigate whether changing a variable between different groups has a specific outcome. For example, imagine you want to find out whether adding fertilizer to soil affects the height of pea plants. You could investigate this question with the following experiment: You grow one group of pea plants in soil with fertilizer and measure the height of the plants. This group shows you what happens when fertilizer is added to soil. Since fertilizer is the variable whose effect you are investigating, this group is an experimental group. You grow another group of pea plants in soil without fertilizer and measure the height of the plants. Since this group shows you what happens when fertilizer is not added to the soil, it is a control group. By comparing the results from the experimental group to the results from the control group, you can conclude whether adding fertilizer to the soil affects pea plant height.

In this experiment, Jeanette and Bryant investigated whether adding wax to snowboards affects their speed. There was no wax on the snowboards with wax removed. So, they were part of a control group.

Experiments have variables, or parts that change. You can design an experiment to investigate whether changing a variable between different groups has a specific outcome. For example, imagine you want to find out whether adding fertilizer to soil affects the height of pea plants. You could investigate this question with the following experiment: You grow one group of pea plants in soil with fertilizer and measure the height of the plants. This group shows you what happens when fertilizer is added to soil. Since fertilizer is the variable whose effect you are investigating, this group is an experimental group. You grow another group of pea plants in soil without fertilizer and measure the height of the plants. Since this group shows you what happens when fertilizer is not added to the soil, it is a control group. By comparing the results from the experimental group to the results from the control group, you can conclude whether adding fertilizer to the soil affects pea plant height. In this experiment, Jeanette and Bryant investigated whether adding wax to snowboards affects their speed. There was no wax on the snowboards with wax removed. So, they were part of a control group.

the snowboards with wax removed

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Which material is this magnifying glass made of?

natural science

A material is a type of matter. Wood, glass, metal, and plastic are common materials. Some objects are made of just one material. Most nails are made of metal. Other objects are made of more than one material. This hammer is made of metal and wood.

Look at the picture of the magnifying glass. The magnifying glass is made of two different materials. The handle is made of plastic, and the lens is made of glass.

A material is a type of matter. Wood, glass, metal, and plastic are common materials. Some objects are made of just one material. Most nails are made of metal. Other objects are made of more than one material. This hammer is made of metal and wood. Look at the picture of the magnifying glass. The magnifying glass is made of two different materials. The handle is made of plastic, and the lens is made of glass.

plastic

19b0a0929e0049759ed0ffdf478bde82

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Select the organism in the same species as the marbled salamander.

natural science

Scientists use scientific names to identify organisms. Scientific names are made of two words. The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits. A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus. Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus. Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur.

A marbled salamander's scientific name is Ambystoma opacum. Ambystoma opacum has the same scientific name as a marbled salamander. So, these organisms are in the same species. Lissotriton helveticus does not have the same scientific name as a marbled salamander. So, Ambystoma opacum and Lissotriton helveticus are not in the same species. Taricha torosa does not have the same scientific name as a marbled salamander. So, Ambystoma opacum and Taricha torosa are not in the same species.

Scientists use scientific names to identify organisms. Scientific names are made of two words. The first word in an organism's scientific name tells you the organism's genus. A genus is a group of organisms that share many traits. A genus is made up of one or more species. A species is a group of very similar organisms. The second word in an organism's scientific name tells you its species within its genus. Together, the two parts of an organism's scientific name identify its species. For example Ursus maritimus and Ursus americanus are two species of bears. They are part of the same genus, Ursus. But they are different species within the genus. Ursus maritimus has the species name maritimus. Ursus americanus has the species name americanus. Both bears have small round ears and sharp claws. But Ursus maritimus has white fur and Ursus americanus has black fur. A marbled salamander's scientific name is Ambystoma opacum. Ambystoma opacum has the same scientific name as a marbled salamander. So, these organisms are in the same species. Lissotriton helveticus does not have the same scientific name as a marbled salamander. So, Ambystoma opacum and Lissotriton helveticus are not in the same species. Taricha torosa does not have the same scientific name as a marbled salamander. So, Ambystoma opacum and Taricha torosa are not in the same species.

Ambystoma opacum

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Select the reptile below.

natural science

Birds, mammals, fish, reptiles, and amphibians are groups of animals. Scientists sort animals into each group based on traits they have in common. This process is called classification. Classification helps scientists learn about how animals live. Classification also helps scientists compare similar animals.

A Nile crocodile is a reptile. It has scaly, waterproof skin. Crocodiles hunt their prey in or near water. A leafy seadragon is a fish. It lives underwater. It has fins, not limbs. A seadragon's body looks like a clump of seaweed. This helps the seadragon hide from its predators. An arroyo toad is an amphibian. It has moist skin and begins its life in water. Toads do not have teeth! They swallow their food whole. A sea otter is a mammal. It has fur and feeds its young milk. Sea otters have very thick fur. Their fur keeps them warm in cold water.

Birds, mammals, fish, reptiles, and amphibians are groups of animals. Scientists sort animals into each group based on traits they have in common. This process is called classification. Classification helps scientists learn about how animals live. Classification also helps scientists compare similar animals. A Nile crocodile is a reptile. It has scaly, waterproof skin. Crocodiles hunt their prey in or near water. A leafy seadragon is a fish. It lives underwater. It has fins, not limbs. A seadragon's body looks like a clump of seaweed. This helps the seadragon hide from its predators. An arroyo toad is an amphibian. It has moist skin and begins its life in water. Toads do not have teeth! They swallow their food whole. A sea otter is a mammal. It has fur and feeds its young milk. Sea otters have very thick fur. Their fur keeps them warm in cold water.

Nile crocodile

82f59e66a712465fa656a8c13c03baaf

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Which animal's feet are also adapted to walk on snow and ice?

natural science

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The shape of an animal's feet is one example of an adaptation. Animals' feet can be adapted in different ways. For example, webbed feet might help an animal swim. Feet with thick fur might help an animal walk on cold, snowy ground.

Look at the picture of the snow leopard. The snow leopard has furry feet with large pads. Its feet are adapted to walk on snow and ice. The fur can help keep the snow leopard's feet warm. The large pads help spread its weight over a larger area. This allows it to walk on ice without slipping and to walk on snow without sinking in too deep. Now look at each animal. Figure out which animal has a similar adaptation. The Siberian tiger has furry feet with large pads. Its feet are adapted to walk on snow and ice. The tokay gecko has wide, sticky toes. Its feet are not adapted to walk on snow and ice. The tokay gecko uses its feet to climb trees and walk on leaves.

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors. The shape of an animal's feet is one example of an adaptation. Animals' feet can be adapted in different ways. For example, webbed feet might help an animal swim. Feet with thick fur might help an animal walk on cold, snowy ground. Look at the picture of the snow leopard. The snow leopard has furry feet with large pads. Its feet are adapted to walk on snow and ice. The fur can help keep the snow leopard's feet warm. The large pads help spread its weight over a larger area. This allows it to walk on ice without slipping and to walk on snow without sinking in too deep. Now look at each animal. Figure out which animal has a similar adaptation. The Siberian tiger has furry feet with large pads. Its feet are adapted to walk on snow and ice. The tokay gecko has wide, sticky toes. Its feet are not adapted to walk on snow and ice. The tokay gecko uses its feet to climb trees and walk on leaves.

Siberian tiger

470a4be06cd54600997d2d31c3795513

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Which property do these four objects have in common?

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification.

Look at each object. For each object, decide if it has that property. An opaque object does not let light through. All four objects are opaque. A flexible object can be folded or bent without breaking easily. The hair clip is flexible, but the building blocks are not. A rough object feels scratchy when you touch it. The hair clip and the binder are not rough. The property that all four objects have in common is opaque.

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it. Different objects can have properties in common. You can use these properties to put objects into groups. Grouping objects by their properties is called classification. Look at each object. For each object, decide if it has that property. An opaque object does not let light through. All four objects are opaque. A flexible object can be folded or bent without breaking easily. The hair clip is flexible, but the building blocks are not. A rough object feels scratchy when you touch it. The hair clip and the binder are not rough. The property that all four objects have in common is opaque.

opaque

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validation_images/image_196.png

Select the bird below.

natural science

Birds, mammals, fish, reptiles, and amphibians are groups of animals. The animals in each group have traits in common. Scientists sort animals into groups based on traits they have in common. This process is called classification.

A flamingo is a bird. It has feathers, two wings, and a beak. A kangaroo is a mammal. It has fur and feeds its young milk.

Birds, mammals, fish, reptiles, and amphibians are groups of animals. The animals in each group have traits in common. Scientists sort animals into groups based on traits they have in common. This process is called classification. A flamingo is a bird. It has feathers, two wings, and a beak. A kangaroo is a mammal. It has fur and feeds its young milk.

flamingo

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validation_images/image_197.png

Is the following statement about our solar system true or false? Jupiter's volume is more than 10,000 times as large as the volume of Mars.

natural science

A planet's volume tells you the size of the planet. The primary composition of a planet is what the planet is made mainly of. In our solar system, planets are made mainly of rock, gas, or ice. The volume of a planet is a very large quantity. Large quantities such as this are often written in scientific notation. For example, the volume of Jupiter is 1,430,000,000,000,000 km^3. In scientific notation, Jupiter's volume is written as 1.43 x 10^15 km^3. To compare two numbers written in scientific notation, first compare their exponents. The bigger the exponent is, the bigger the number is. For example: 1.43 x 10^15 is larger than 1.43 x 10^12 If their exponents are equal, compare the first numbers. For example: 1.43 x 10^15 is larger than 1.25 x 10^15 To multiply a number written in scientific notation by a power of 10, write the multiple of 10 as 10 raised to an exponent. Then, add the exponents. For example: 1.43 x 10^15 · 1000 = 1.43 x 10^15 · 10^3 = 1.43 x 10^(15 + 3) = 1.43 x 10^18

To determine if this statement is true, calculate the value of 10,000 times the volume of Mars. Then compare the result to the volume of Jupiter. Jupiter's volume is 1.43 x 10^15 km^3, which is less than 1.63 x 10^15 km^3. So, Jupiter's volume is less than 10,000 times as large as the volume of Mars.

A planet's volume tells you the size of the planet. The primary composition of a planet is what the planet is made mainly of. In our solar system, planets are made mainly of rock, gas, or ice. The volume of a planet is a very large quantity. Large quantities such as this are often written in scientific notation. For example, the volume of Jupiter is 1,430,000,000,000,000 km^3. In scientific notation, Jupiter's volume is written as 1.43 x 10^15 km^3. To compare two numbers written in scientific notation, first compare their exponents. The bigger the exponent is, the bigger the number is. For example: 1.43 x 10^15 is larger than 1.43 x 10^12 If their exponents are equal, compare the first numbers. For example: 1.43 x 10^15 is larger than 1.25 x 10^15 To multiply a number written in scientific notation by a power of 10, write the multiple of 10 as 10 raised to an exponent. Then, add the exponents. For example: 1.43 x 10^15 · 1000 = 1.43 x 10^15 · 10^3 = 1.43 x 10^(15 + 3) = 1.43 x 10^18 To determine if this statement is true, calculate the value of 10,000 times the volume of Mars. Then compare the result to the volume of Jupiter. Jupiter's volume is 1.43 x 10^15 km^3, which is less than 1.63 x 10^15 km^3. So, Jupiter's volume is less than 10,000 times as large as the volume of Mars.

false

70b4392a82c647c99855f08e18874f46

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Think about the magnetic force between the magnets in each pair. Which of the following statements is true?

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by changing the distance between them. The magnitude of the magnetic force is greater when there is a smaller distance between the magnets.

Distance affects the magnitude of the magnetic force. When there is a smaller distance between magnets, the magnitude of the magnetic force between them is greater. There is a smaller distance between the magnets in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is greater in Pair 2 than in Pair 1.

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart. These pulls and pushes between magnets are called magnetic forces. The strength of a force is called its magnitude. The greater the magnitude of the magnetic force between two magnets, the more strongly the magnets attract or repel each other. You can change the magnitude of a magnetic force between two magnets by changing the distance between them. The magnitude of the magnetic force is greater when there is a smaller distance between the magnets. Distance affects the magnitude of the magnetic force. When there is a smaller distance between magnets, the magnitude of the magnetic force between them is greater. There is a smaller distance between the magnets in Pair 2 than in Pair 1. So, the magnitude of the magnetic force is greater in Pair 2 than in Pair 1.

The magnitude of the magnetic force is greater in Pair 2.

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Which better describes the Pisgah National Forest ecosystem?

natural science

An environment includes all of the biotic, or living, and abiotic, or nonliving, things in an area. An ecosystem is created by the relationships that form among the biotic and abiotic parts of an environment. There are many different types of terrestrial, or land-based, ecosystems. Here are some ways in which terrestrial ecosystems can differ from each other: the pattern of weather, or climate the type of soil the organisms that live there

A temperate deciduous forest is a type of ecosystem. Temperate deciduous forests have the following features: warm, wet summers and cold, wet winters, soil that is rich in nutrients, and only a few types of trees. So, the Pisgah National Forest has soil that is rich in nutrients. It also has only a few types of trees.

An environment includes all of the biotic, or living, and abiotic, or nonliving, things in an area. An ecosystem is created by the relationships that form among the biotic and abiotic parts of an environment. There are many different types of terrestrial, or land-based, ecosystems. Here are some ways in which terrestrial ecosystems can differ from each other: the pattern of weather, or climate the type of soil the organisms that live there A temperate deciduous forest is a type of ecosystem. Temperate deciduous forests have the following features: warm, wet summers and cold, wet winters, soil that is rich in nutrients, and only a few types of trees. So, the Pisgah National Forest has soil that is rich in nutrients. It also has only a few types of trees.

It has soil that is rich in nutrients. It also has only a few types of trees.

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