Question: What evidence of a wildfire does this picture show?

Choices:
- The grass is brown and dry.
- Some of the grass on the ground is burning.

This picture was taken during a wildfire. A wildfire happens when a natural area catches fire and burns.

natural science

Find evidence of changes to Earth's surface

Evidence is information that tells you something happened.
How do you look for evidence of a change to Earth's surface?
There are many ways to find evidence of a change to Earth's surface. One way is to look at a picture that was taken after the change.
Here are some examples of what the evidence for different changes might be:
Cause of the change | Evidence of the change
earthquake | cracks in the ground; houses with broken walls and roofs
volcanic eruption | melted rock on Earth's surface; smoke coming out of a hole in the ground
erosion | a canyon with a river flowing through it; a river carrying sand and mud
Be careful when you are looking for evidence!
A picture of Earth's surface can contain a lot of information. Some of that information might be evidence of a change to the surface, but some of it is not!
For example, a picture taken after an earthquake might show a blue sky. But the color of the sky is not evidence of an earthquake. So, that information is not evidence that an earthquake happened.


Question: What can Austen and Naomi trade to each get what they want?

Choices:
- Naomi can trade her broccoli for Austen's oranges.
- Austen can trade his tomatoes for Naomi's broccoli.
- Austen can trade his tomatoes for Naomi's sandwich.
- Naomi can trade her almonds for Austen's tomatoes.

Trade happens when people agree to exchange goods and services. People give up something to get something else. Sometimes people barter, or directly exchange one good or service for another.
Austen and Naomi open their lunch boxes in the school cafeteria. Both of them could be happier with their lunches. Austen wanted broccoli in his lunch and Naomi was hoping for tomatoes. Look at the images of their lunches. Then answer the question below.

social science

Solution:
Austen wanted broccoli in his lunch and Naomi was hoping for tomatoes. Look at the labeled part of the images.
Austen has tomatoes. Naomi has broccoli. They can trade tomatoes for broccoli to both be happier. Trading other things would not help either person get more items they want.


Question: Will these magnets attract or repel each other?

Choices:
- repel
- attract

Two magnets are placed as shown.

Hint: Magnets that attract pull together. Magnets that repel push apart.

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.

Solution:
Will these magnets attract or repel? To find out, 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. Poles that are different attract. So, these magnets will attract each other.


Question: Based on the arrows, which of the following organisms is a consumer?

Choices:
- mushroom
- lichen

Below is a food web from a tundra ecosystem in Nunavut, a territory in Northern Canada.
A food web models how the matter eaten by organisms moves through an ecosystem. The arrows in a food web represent how matter moves between organisms in an ecosystem.

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.

Solution:
Consumers eat other organisms. So, there are arrows in a food web that point from other organisms to consumers.
The mushroom has arrows pointing to it from the barren-ground caribou and the grizzly bear. So, the mushroom is a consumer.
The lichen does not have any arrows pointing to it. So, the lichen is a producer, not a consumer.


Question: Which solution has a higher concentration of pink particles?

Choices:
- neither; their concentrations are the same
- Solution B
- Solution A

The diagram below is a model of two solutions. Each pink ball represents one particle of solute.

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

Solution:
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.


Question: Identify the question that Robert's experiment can best answer.

Choices:
- Do steel nails take fewer days to rust in water compared to vinegar?
- Do steel nails rust in fewer days when submerged in a large volume of liquid compared to a small volume?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Robert put one two-inch steel nail into each of six test tubes. He added water to three of the test tubes and vinegar to the other three. In each test tube, he completely covered the nail with the same volume of liquid. Robert checked the nails for rust at the same time every day. He recorded how many days it took each nail to become completely covered in rust. Then, he compared the number of days it took nails to rust in water to the number of days it took nails to rust in vinegar.
Figure: a new steel nail on a pile of rusty nails.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question: Does this passage describe the weather or the climate?

Choices:
- weather
- climate

Figure: Canary Islands.
It was partly cloudy in the Canary Islands last Tuesday.
Hint: Weather is what the atmosphere is like at a certain place and time. Climate is the pattern of weather in a certain place.

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.

Solution:
Read the passage carefully.
It was partly cloudy in the Canary Islands last Tuesday.
This passage tells you about the cloud cover over the Canary Islands last Tuesday. This passage describes the atmosphere at a certain place and time. So, this passage describes the weather.


Question: Which country is highlighted?

Choices:
- Haiti
- Trinidad and Tobago
- Cuba
- the Dominican Republic

social science

Identify and select countries of the Caribbean

Solution:
This country is Haiti.
Does Haiti have any territorial disputes?
Haiti claims to own Navassa Island, which is a disputed territory. In other words, multiple countries or groups claim that the area rightfully belongs to them.
Navassa Island is also claimed by the United States. The United States claimed the island in 1857 and has controlled it since then. But Haiti considers the island part of its territory and has protested the United States' claim since this time. No one lives on the island. Today, it is a nature preserve.


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

Choices:
- neither; the samples have the same temperature
- sample B
- sample A

The diagrams below show two pure samples of gas in identical closed, rigid containers. Each colored ball represents one gas particle. Both samples have the same number of particles.

natural science

Identify how particle motion affects temperature and pressure

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.

Solution:
The particles in both samples have the same average speed, but each particle in sample B has more mass than each particle 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.


Question: Which solution has a higher concentration of green particles?

Choices:
- Solution B
- neither; their concentrations are the same
- Solution A

The diagram below is a model of two solutions. Each green ball represents one particle of solute.

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

Solution:
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 and Solution B have the same number of green particles per milliliter. So, their concentrations are the same.


Question: What is the name of the colony shown?

Choices:
- Pennsylvania
- Vermont
- Tennessee
- Michigan

social science

Solution: The colony is Pennsylvania.


Question: What is the capital of Hawaii?

Choices:
- Hilo
- Carson City
- Honolulu
- Juneau

social science

Solution: Honolulu is the capital of Hawaii.


Question: In this food chain, the yucca moth is a consumer. Why?

Choices:
- It makes its own food.
- It eats another living thing.

This diagram shows a food chain from a desert ecosystem in Southern California.

natural science

Every living thing needs food to stay alive. Living things get their food in different ways. A food chain shows how living things in an ecosystem get their food.
Producers make their own food. Many producers use carbon dioxide, water, and sunlight to make sugar. This sugar is food for the producer.
Consumers eat other living things. Consumers cannot make their own food.

Solution: In this food chain, the yucca moth is a consumer because it eats another living thing. The yucca moth in this food chain eats the Mojave yucca.


Question: What is the capital of Kentucky?

Choices:
- Lexington
- Frankfort
- Anchorage
- Baton Rouge

social science

Identify state capitals of the Southeast

Solution: Frankfort is the capital of Kentucky.


Question: Can Polytrichum commune cells make their own food?

Choices:
- yes
- no

This organism is Polytrichum commune. It is a member of the plant kingdom.
Polytrichum commune is also called the common haircap moss. This plant gets its common name from its brown, cap-like structures. Those structures contain spores. After the spores are released, they can settle on the ground and grow into new mosses.

natural science

Describe, classify, and compare kingdoms

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

Solution: Polytrichum commune is a plant. Plant cells can make their own food. Plant cells make food using photosynthesis.


Question: Select the amphibian below.

Choices:
- brown tree frog
- woodpecker

Amphibians have moist skin and begin their lives in water. An American bullfrog is an example of an amphibian.

natural science

Identify mammals, birds, fish, reptiles, and amphibians

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.

Solution:
A brown 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 woodpecker is a bird. It has feathers, two wings, and a beak.
Woodpeckers have strong beaks. They use their beaks to drill into wood to hunt for food.


Question:
Complete the statement.
Beryllium is ().

Choices:
- an elementary substance
- a compound

The model below represents beryllium. ryllium is a strong, lightweight metal used to make mirrors for space telescopes.

natural science

Classify elementary substances and compounds using models

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 elementary substance zirconium.
In a space-filling model, the balls represent atoms that are bonded together. The color of a ball represents a specific chemical element. The atomic symbol for that chemical element is shown in the legend.

Solution:
Use the model to determine whether beryllium is an elementary substance or a compound.
Step 1: Interpret the model.
In the space-filling model shown above, all of the balls are the same color:
. The legend shows that light green represents the chemical element with the atomic symbol Be. So, the model shows you that beryllium is composed of one chemical element.
Step 2: Determine whether the substance is an elementary substance or a compound.
You know from Step 1 that beryllium is composed of only one chemical element. So, beryllium is an elementary substance.


Question: Which of the following could Edwin's test show?

Choices:
- how much athletes would sweat in the fabric
- if the sample fabric would absorb one drop of water in less than one second
- how long it would take the sample fabric to dry after it absorbed one drop of water

People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design.
The passage below describes how the engineering-design process was used to test a solution to a problem. Read the passage. Then answer the question below.

Edwin, a materials engineer, was developing a quick-drying fabric for athletic clothing. The fabric needed to absorb one drop of water in less than one second and dry completely in less than five minutes. Edwin thought a fabric made from cotton and polyester would both absorb water well and dry quickly. But he needed to decide what percentage of each material to use.
So, he made a sample fabric that was 50% cotton and 50% polyester. Then he put one drop of water on the sample. He timed how long it took the fabric to dry after the water was absorbed.
Figure: fabric that has not absorbed drops of water.

natural science

Evaluate tests of engineering-design solutions

People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design. How can you determine what a test can show? You need to figure out what was tested and what was measured.
Imagine an engineer needs to design a bridge for a windy location. She wants to make sure the bridge will not move too much in high wind. So, she builds a smaller prototype, or model, of a bridge. Then, she exposes the prototype to high winds and measures how much the bridge moves.
First, identify what was tested. A test can examine one design, or it may compare multiple prototypes to each other. In the test described above, the engineer tested a prototype of a bridge in high wind.
Then, identify what the test measured. One of the criteria for the bridge was that it not move too much in high winds. The test measured how much the prototype bridge moved.
Tests can show how well one or more designs meet the criteria. The test described above can show whether the bridge would move too much in high winds.


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

Choices:
- sample A
- sample B
- neither; the samples have the same temperature

The diagrams below show two pure samples of gas in identical closed, rigid containers. Each colored ball represents one gas particle. Both samples have the same number of particles.

natural science

Identify how particle motion affects temperature and pressure

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.

Solution:
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.


Question: What is the capital of Massachusetts?

Choices:
- Dover
- Boston
- Salem
- Augusta

social science

Identify state capitals of the Northeast

Solution: Boston is the capital of Massachusetts.


Question: What is the Morelet's crocodile's scientific name?

Choices:
- Crocodylus moreletii
- Crocodylus anthropophagus

The Morelet's crocodile lives in South America. Its scientific name refers to P. M. A. Morelet, the French naturalist who first identified the crocodile in 1850. A naturalist is a scientist who observes and studies organisms in their environments.

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.

Solution:
This organism's scientific name refers to P. M. A. Morelet.
The word moreletii refers to P. M. A. Morelet. So, the Morelet's crocodile's scientific name is Crocodylus moreletii.


Question: Which material is this flower vase made of?

Choices:
- silk
- glass

natural science

A material is a type of matter. Wood, glass, metal, and plastic are common materials.

Solution:
Look at the picture of the flower vase.
The flower vase is made of glass.
Glass is a clear, breakable material. If you knock over a glass flower vase, it might break.


Question: Will these magnets attract or repel each other?

Choices:
- repel
- attract

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.

Solution:
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.


Question: What is the capital of Kansas?

Choices:
- Wichita
- Pierre
- Springfield
- Topeka

social science

Solution: Topeka is the capital of Kansas.


Question: Which property do these three objects have in common?

Choices:
- translucent
- opaque
- fragile

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.

Solution:
Look at each object.
For each object, decide if it has that property.
A translucent object lets light through. But you cannot see clearly through a translucent object. None of the objects are translucent.
A fragile object will break into pieces if you drop it. None of the objects are fragile.
An opaque object does not let light through. All three objects are opaque.
The property that all three objects have in common is opaque.


Question: What can Turner and Mona trade to each get what they want?

Choices:
- Turner can trade his tomatoes for Mona's broccoli.
- Turner can trade his tomatoes for Mona's carrots.
- Mona can trade her broccoli for Turner's oranges.
- Mona can trade her almonds for Turner's tomatoes.

Trade happens when people agree to exchange goods and services. People give up something to get something else. Sometimes people barter, or directly exchange one good or service for another.
Turner and Mona open their lunch boxes in the school cafeteria. Neither Turner nor Mona got everything that they wanted. The table below shows which items they each wanted:

Look at the images of their lunches. Then answer the question below.
Turner's lunch Mona's lunch

social science

Solution:
Look at the table and images.
Turner wants broccoli. Mona wants tomatoes. They can trade tomatoes for broccoli to both get what they want. Trading other things would not help both people get more items they want.


Question: Which property matches this object?

Choices:
- stretchy
- transparent

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.

Solution:
Look at the object.
Think about each property.
You can see clearly through a transparent object. The fish bowl is transparent.
A stretchy object gets longer when you pull on it. The fish bowl is not stretchy.


Question: Which country is highlighted?

Choices:
- Tuvalu
- Australia
- New Zealand
- Papua New Guinea

social science

Identify and select countries of Oceania

Solution:
This country is Australia.
Is Australia a country or a continent?
Both! Australia is a country in Oceania, a region made up of many lands and islands in the Pacific Ocean. Many people say that Australia is the world's smallest continent. But some people call Oceania a continent instead.


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

Choices:
- neither; the samples have the same temperature
- sample A
- sample B

The diagrams below show two pure samples of gas in identical closed, rigid containers. Each colored ball represents one gas particle. Both samples have the same number of particles.

natural science

Identify how particle motion affects temperature and pressure

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.


Question: Does this passage describe the weather or the climate?

Choices:
- climate
- weather

Figure: Blue Nile Falls.
Blue Nile Falls is in Ethiopia. The winds in this part of Africa usually blow from the southeast.
Hint: Weather is what the atmosphere is like at a certain place and time. Climate is the pattern of weather in a certain place.

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.

Solution:
Read the passage carefully.
Blue Nile Falls is in Ethiopia. The winds in this part of Africa usually blow from the southeast.
The underlined part of the passage tells you about the usual wind patterns at Blue Nile Falls. This passage does not describe what the weather is like on a particular day. So, this passage describes the climate.


Question: Which material is this egg carton made of?

Choices:
- wood
- styrofoam

natural science

A material is a type of matter. Wood, glass, metal, and plastic are common materials.

Solution:
Look at the picture of the egg carton.
The egg carton is made of styrofoam.
Not all egg cartons are made of styrofoam. Some egg cartons are made of soft, gray cardboard.


Question: What is the capital of Florida?

Choices:
- Tampa
- Little Rock
- Laramie
- Tallahassee

social science

Identify state capitals of the Southeast

Solution: Tallahassee is the capital of Florida.


Question: Identify the question that Kira's experiment can best answer.

Choices:
- Does linen fabric turn darker than cotton fabric when soaked in a mixture of black dye and water?
- Does fabric turn darker when soaked in a mixture of black dye and water for 15 minutes compared to 30 minutes?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Kira prepared ten buckets, each with one gallon of boiling water and three tablespoons of black fabric dye. Kira soaked white linen fabric squares in five of the buckets, and white cotton fabric squares in the other five buckets. All of the fabric squares were soaked for 15 minutes. After the fabric dried, Kira scored the darkness of the squares on a scale from light to dark. She compared the darkness of the linen fabric to the darkness of the cotton fabric.
Figure: fabric that has been dyed black.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question: Which country is highlighted?

Choices:
- the Federated States of Micronesia
- New Zealand
- Tuvalu
- Tonga

social science

Identify and select countries of Oceania

Solution: This country is Tuvalu.


Question: Which property do these three objects have in common?

Choices:
- shiny
- fuzzy
- blue

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.

Solution:
Look at each object.
For each object, decide if it has that property.
A shiny object reflects a lot of light. You can usually see your reflection in a shiny object. All three objects are shiny.
A fuzzy object is covered in soft hair. None of the objects are fuzzy.
Blue is a color.
This color is blue. None of the objects are blue.
The property that all three objects have in common is shiny.


Question: What is the name of the colony shown?

Choices:
- Maryland
- Virginia
- Washington, D.C.
- Rhode Island

social science

Solution: The colony is Maryland.


Question: Which of these states is farthest east?

Choices:
- Nebraska
- Louisiana
- Idaho
- Arizona

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.

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


Question: Which country is highlighted?

Choices:
- The Bahamas
- Cuba
- Jamaica
- Haiti

social science

Identify and select countries of the Caribbean

Solution:
This country is Cuba.
Does Cuba have any territorial disputes?
Cuba claims to own Guantanamo Bay Naval Base, which is a disputed territory. In other words, multiple countries or groups claim that the area rightfully belongs to them.
The United States controls the area and uses it as a military base and prison. A treaty in 1903 gave the U.S. the right to rent the land from Cuba. But today, Cuba says that it had no choice but to accept the treaty. It wants the United States to leave the area and does not accept the rent money sent by the United States each year.


Question: Which month is the hottest on average in Rome?

Choices:
- December, January, and February
- July and August
- March and April

Use the graph to answer the question below.

natural science

Scientists record climate data from places around the world. Temperature is one type of climate data. Scientists collect data over many years. They can use this data to calculate the average temperature for each month. The average temperature can be used to describe the climate of a location.
A line graph can be used to show the average temperature each month. Months with higher dots on the graph have higher average temperatures.

Solution:
To describe the average temperature trends in Rome, look at the graph.
Choice "Feb" is incorrect.
Choice "Mar" is incorrect.
Choice "Apr" is incorrect.
Choice "Jul" is incorrect.
Choice "Aug" is incorrect.
Choice "Dec" is incorrect.
Choice "Jan" is incorrect.
The average temperatures in July and August are around 23°C. These months have the highest average temperatures of all of the months. So, they are the hottest months on average.


Question: What is the name of the colony shown?

Choices:
- New York
- Rhode Island
- North Carolina
- New Jersey

social science

Solution: The colony is Rhode Island.


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

Choices:
- tiger
- marmot

Cougars are carnivores, or meat eaters. They eat mammals such as deer and rabbits. The 's mouth is adapted to tear through meat.
Figure: cougar.

natural science

Animal adaptations: beaks, mouths, and necks

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.

Solution:
Look at the picture of the cougar.
The cougar has a large mouth and sharp teeth. Its mouth is adapted to tear through meat. The cougar 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.


Question: Is the water in a sink a solid or a liquid?

Choices:
- a liquid
- a solid

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.

Solution:
The water in a sink is a liquid. A liquid takes the shape of any container it is in.
If you move the water from a sink into a different container, the water will take the shape of that container. But the water will still take up the same amount of space.


Question: What is the capital of Maryland?

Choices:
- Juneau
- Augusta
- Annapolis
- Providence

social science

Identify state capitals of the Northeast

Solution: Annapolis is the capital of Maryland.


Question: Which country is highlighted?

Choices:
- Palau
- Nauru
- the Federated States of Micronesia
- New Zealand

social science

Identify and select countries of Oceania

Solution: This country is Palau.


Question: What is the capital of Utah?

Choices:
- Helena
- Albany
- Salt Lake City
- Provo

social science

Solution: Salt Lake City is the capital of Utah.


Question: What is the capital of New Jersey?

Choices:
- Newark
- Montpelier
- Jersey City
- Trenton

social science

Identify state capitals of the Northeast

Solution: Trenton is the capital of New Jersey.


Question: Which of the following organisms is the decomposer in this food web?

Choices:
- green algae
- water mold
- golden algae

Below is a food web from Little Rock Lake, a freshwater lake ecosystem in Wisconsin.
A food web models how the matter eaten by organisms moves through an ecosystem. The arrows in a food web represent how matter moves between organisms in an ecosystem.

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.

Solution:
Decomposers help break down dead organisms into simpler matter, such as nutrients. These nutrients can then help plants and other organisms grow. In a food web, there is an arrow pointing from another organism to a decomposer. There are no arrows pointing from a decomposer to another organism.
The water mold does not have arrows pointing from it to other organisms. So, the water mold is a decomposer.
The bacteria do not have arrows pointing from them to other organisms. So, the bacteria are decomposers.
The green algae has arrows pointing from it. So, the green algae is not a decomposer.
The golden algae has an arrow pointing from it. So, the golden algae is not a decomposer.


Question: Select the organism in the same genus as the North American beaver.

Choices:
- Goura scheepmakeri
- Castor fiber
- Cervus canadensis

This organism is a North American beaver. Its scientific name is Castor canadensis.

natural science

Use scientific names to classify organisms

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.

Solution:
A North American beaver's scientific name is Castor canadensis. The first word of its scientific name is Castor.
Cervus canadensis and Castor canadensis are not in the same genus.
These organisms are not in the same genus, but part of their scientific names is the same. Cervus canadensis and Castor canadensis have the same species name within their genus, canadensis. But the first words of their scientific names are different. Cervus canadensis is in the genus Cervus, and Castor canadensis is in the genus Castor.
Castor fiber is in the genus Castor. The first word of its scientific name is Castor. So, Castor fiber and Castor canadensis are in the same genus.
Goura scheepmakeri is in the genus Goura. The first word of its scientific name is Goura. So, Goura scheepmakeri and Castor canadensis are not in the same genus.


Question: Which animal is also adapted to be camouflaged in the snow?

Choices:
- Arctic hare
- camel

Polar bears live in and around the cold Arctic Ocean. The  is adapted to be camouflaged in the snow.
Figure: polar bear.

natural science

Animal adaptations: skins and body coverings

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.

Solution:
Look at the picture of the polar bear.
The polar bear has white fur covering its body. It is adapted to be camouflaged in the snow. The word camouflage means to blend in.
Now look at each animal. Figure out which animal has a similar adaptation.
During the winter, the Arctic hare has white fur covering its body. It is adapted to be camouflaged in the snow.
The camel has sand-colored fur covering its skin. It is not adapted to be camouflaged in the snow.


Question: Which ocean is highlighted?

Choices:
- the Indian Ocean
- the Atlantic Ocean
- the Pacific Ocean
- the Southern Ocean

social science

Oceans are huge bodies of salt water. The world has five oceans. All of the oceans are connected, making one world ocean.

Solution: This is the Atlantic Ocean.


Question: Which type of relationship is formed when a bristle worm lives on a white sea urchin?

Choices:
- mutualistic
- commensal
- parasitic

Read the passage. Then answer the question.

White sea urchins live in tropical oceans. Sea urchins are covered with hard, sharp spines. These spear-like spines protect the sea urchin from predators, such as fish. Sometimes a small worm, called a bristle worm, also uses the spines for protection.
The worm lives on the sea urchin, between the spines. To attack a worm on the sea urchin's body, a fish would have to get past the spines. When the worm lives on the sea urchin, the worm does not change the sea urchin's ability to survive.
Figure: a white sea urchin in the ocean.

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)

Solution:
When a bristle worm lives on a white sea urchin, the worm is protected from predators by the sea urchin's sharp spines. So, the worm benefits from its relationship with the sea urchin.
The sea urchin's ability to survive does not change when a worm lives on it. So, the sea urchin is not significantly affected by its relationship with the worm.
Since the worm benefits and the sea urchin is not significantly affected, a commensal relationship is formed when a bristle worm lives on a white sea urchin.


Question: Which property do these three objects have in common?

Choices:
- rough
- yellow
- sticky

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.

Solution:
Look at each object.
For each object, decide if it has that property.
A rough object feels scratchy when you touch it. The rain boots and the rubber duck are not rough.
A sticky object can attach or stick to other things. The rain boots and the rubber duck are not sticky.
Yellow is a color.
This color is yellow. All three objects are yellow.
The property that all three objects have in common is yellow.


Question: Which of these states is farthest east?

Choices:
- Georgia
- Delaware
- North Dakota
- Colorado

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.

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


Question: Which is this organism's scientific name?

Choices:
- Carcharodon carcharias
- great white shark

This organism is a great white shark. It is also called Carcharodon carcharias.

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.

Solution:
Carcharodon carcharias is written in italics. The first word is capitalized, and the second word is not.
So, Carcharodon carcharias is the scientific name.


Question: Which month is the wettest on average in Christchurch?

Choices:
- August
- April
- May

Use the graph to answer the question below.

natural science

Scientists record climate data from places around the world. Precipitation, or rain and snow, is one type of climate data.
A bar graph can be used to show the average amount of precipitation each month. Months with taller bars have more precipitation on average.

Solution:
To describe the average precipitation trends in Christchurch, look at the graph.
Choice "Apr" is incorrect.
Choice "May" is incorrect.
Choice "Aug" is incorrect.
May has an average monthly precipitation of about 70 millimeters. This is higher than in any other month. So, May is the wettest month on average.


Question: Will these magnets attract or repel each other?

Choices:
- repel
- attract

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.

Solution:
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.


Question: Which ocean is highlighted?

Choices:
- the Southern Ocean
- the Pacific Ocean
- the Atlantic Ocean
- the Indian Ocean

social science

Oceans are huge bodies of salt water. The world has five oceans. All of the oceans are connected, making one world ocean.

Solution:
This is the Southern Ocean.
The Southern Ocean reaches from the shores of Antarctica to 60° South latitude.


Question: What is the capital of Colorado?

Choices:
- Olympia
- Denver
- Carson City
- Louisville

social science

Solution: Denver is the capital of Colorado.


Question: Which country is highlighted?

Choices:
- Australia
- the Marshall Islands
- New Zealand
- Papua New Guinea

social science

Identify and select countries of Oceania

Solution: This country is New Zealand.


Question: Which of these states is farthest south?

Choices:
- Missouri
- Michigan
- Maine
- Oregon

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.

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


Question: Which of these cities is marked on the map?

Choices:
- Miami
- Atlanta
- Nashville
- Oklahoma City

social science

Solution: The city is Atlanta, Georgia. Oklahoma City, Nashville, and Miami are marked with gray circles on the map below.


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

Choices:
- sea cucumber
- sea otter
- phytoplankton

Below is a food web from an ocean ecosystem in Monterey Bay, off the coast of California.
A food web models how the matter eaten by organisms moves through an ecosystem. The arrows in a food web represent how matter moves between organisms in an ecosystem.

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.

Solution: 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.There are four paths matter can take from the phytoplankton to the bat star: phytoplankton->zooplankton->kelp bass->bat star. phytoplankton->zooplankton->plainfin midshipman->kelp bass->bat star. phytoplankton->zooplankton->black rockfish->kelp bass->bat star. phytoplankton->plainfin midshipman->kelp bass->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. sea otter. 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.. 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 cucumber to the bat star..


Question: Identify the question that Dakota's experiment can best answer.

Choices:
- Do more tomato seedlings grow when they are planted in soil with fertilizer compared to soil without fertilizer?
- Does the humidity level where tomato seeds are planted affect the number of tomato seedlings that grow?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Dakota planted 25 tomato seeds one-half inch below the soil surface in each of six pots. Dakota added an equal amount of fertilizer to three of the six pots. She placed the pots in a plant growth chamber where all the seeds experienced the same temperature, amount of light, and humidity level. After two weeks, Dakota counted the number of seedlings that grew in each pot. She compared the number of seedlings in the pots with fertilizer to the number of seedlings in the pots without fertilizer.
Figure: tomato seedlings growing in soil.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question: What is the capital of California?

Choices:
- Sacramento
- Reno
- Los Angeles
- San Francisco

social science

Solution: Sacramento is the capital of California.


Question: Which continent is highlighted?

Choices:
- Australia
- Africa
- South America
- Europe

social science

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

Solution: This continent is South America.


Question: Identify the question that Harry's experiment can best answer.

Choices:
- Do steel nails take fewer days to rust in water compared to vinegar?
- Do steel nails rust in fewer days when submerged in a large volume of liquid compared to a small volume?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Harry put one two-inch steel nail into each of six test tubes. He added water to three of the test tubes and vinegar to the other three. In each test tube, he completely covered the nail with the same volume of liquid. Harry checked the nails for rust at the same time every day. He recorded how many days it took each nail to become completely covered in rust. Then, he compared the number of days it took nails to rust in water to the number of days it took nails to rust in vinegar.
Figure: a new steel nail on a pile of rusty nails.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question:
Is the following statement about our solar system true or false?
Of the four smallest planets, two are made mainly of gas.

Choices:
- false
- true

Use the data to answer the question below.

natural science

Analyze data to compare properties of planets

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, 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

Solution:
To decide which four planets are the smallest, look at the volumes and compare the exponents. The volumes of Mercury, Venus, Earth, and Mars have the smallest exponents. So, these four planets are the smallest.
These four planets are made mainly of rock. So, of the four smallest planets, none are made mainly of gas.


Question: What is the capital of Colorado?

Choices:
- Denver
- Concord
- Columbia
- Charlotte

social science

Solution: Denver is the capital of Colorado.


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

Choices:
- The magnitude of the magnetic force is greater in Pair 2.
- The magnitude of the magnetic force is greater in Pair 1.
- The magnitude of the magnetic force is the same in both pairs.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material, but some of them are different sizes and shapes.

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.

Solution:
The magnets in Pair 2 attract. The magnets in Pair 1 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 1 than in Pair 2. So, the magnitude of the magnetic force is greater in Pair 1 than in Pair 2.


Question: What is the expected ratio of offspring with a normal-sized body to offspring with a dwarf body? Choose the most likely ratio.

Choices:
- 1:3
- 4:0
- 0:4
- 2:2
- 3:1

In a group of rats, some individuals have a normal-sized body and others have a dwarf body. In this group, the gene for the body size trait has two alleles. The allele for a dwarf body (b) is recessive to the allele for a normal-sized body (B).
This Punnett square shows a cross between two rats.

natural science

Use Punnett squares to calculate ratios of offspring types

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.

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


Question: Select the fish below.

Choices:
- water buffalo
- poison dart frog
- great white shark
- penguin

Fish live underwater. They have fins, not limbs.
Fish are cold-blooded. The body temperature of cold-blooded animals depends on their environment.
A Banggai cardinalfish is an example of a fish.

natural science

Identify mammals, birds, fish, reptiles, and amphibians

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.

Solution:
A penguin is a bird. It has feathers, two wings, and a beak.
Penguins live near water. Penguins cannot fly! They use their wings to swim.
A water buffalo is a mammal. It has hair and feeds its young milk.
Water buffaloes live in Asia. Some people raise water buffaloes for their milk.
A great white shark is a fish. It lives underwater. It has fins, not limbs.
Great white sharks can live for up to 70 years.
A poison dart frog is an amphibian. It has moist skin and begins its life in water.
Poison dart frogs come in many bright colors. Their bright color warns other animals that these frogs are poisonous.


Question: What can Clara and Harry trade to each get what they want?

Choices:
- Harry can trade his almonds for Clara's tomatoes.
- Clara can trade her tomatoes for Harry's carrots.
- Harry can trade his broccoli for Clara's oranges.
- Clara can trade her tomatoes for Harry's broccoli.

Trade happens when people agree to exchange goods and services. People give up something to get something else. Sometimes people barter, or directly exchange one good or service for another.
Clara and Harry open their lunch boxes in the school cafeteria. Neither Clara nor Harry got everything that they wanted. The table below shows which items they each wanted:

Look at the images of their lunches. Then answer the question below.
Clara's lunch Harry's lunch

social science

Solution:
Look at the table and images.
Clara wants broccoli. Harry wants tomatoes. They can trade tomatoes for broccoli to both get what they want. Trading other things would not help both people get more items they want.


Question: Which property do these two objects have in common?

Choices:
- sour
- stretchy

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.

Solution:
Look at each object.
For each object, decide if it has that property.
A lemon has a sour taste. Both objects are sour.
A stretchy object gets longer when you pull on it. Neither of the objects are stretchy.
The property that both objects have in common is sour.


Question: What is the name of the colony shown?

Choices:
- North Carolina
- Mississippi
- New York
- Massachusetts

social science

Solution:
The colony is New York.
During the colonial era, New Hampshire and New York both claimed the territory that would later become the state of Vermont. Vermont was never its own colony.


Question: What is the name of the colony shown?

Choices:
- Massachusetts
- Virginia
- Georgia
- New Hampshire

social science

Solution:
The colony is Virginia.
The Virginia Colony included land that would later become part of the state of West Virginia. West Virginia was never its own colony.


Question: Which of the following could Charlotte's test show?

Choices:
- if the blade guards would break in a crash
- if adding the blade guards made the drone fly poorly
- how much the drone weighed with the blade guards

People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design.
The passage below describes how the engineering-design process was used to test a solution to a problem. Read the passage. Then answer the question below.

Charlotte was designing small aircraft called drones to pick up items from warehouse shelves. She knew that the drones' propeller blades would get damaged if they bumped into anything while flying through the warehouse. So, Charlotte wanted to add blade guards to protect the propeller blades. The guards had to be sturdy so they would not break in a crash. But she thought that if the guards weighed too much, the drones would not fly well.
So, Charlotte put guards made of lightweight metal on one drone. Then she observed how well the drone flew with the guards.
Figure: a drone without blade guards.

natural science

Evaluate tests of engineering-design solutions

People can use the engineering-design process to develop solutions to problems. One step in the process is testing if a potential solution meets the requirements of the design. How can you determine what a test can show? You need to figure out what was tested and what was measured.
Imagine an engineer needs to design a bridge for a windy location. She wants to make sure the bridge will not move too much in high wind. So, she builds a smaller prototype, or model, of a bridge. Then, she exposes the prototype to high winds and measures how much the bridge moves.
First, identify what was tested. A test can examine one design, or it may compare multiple prototypes to each other. In the test described above, the engineer tested a prototype of a bridge in high wind.
Then, identify what the test measured. One of the criteria for the bridge was that it not move too much in high winds. The test measured how much the prototype bridge moved.
Tests can show how well one or more designs meet the criteria. The test described above can show whether the bridge would move too much in high winds.


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

Choices:
- The magnitude of the magnetic force is greater in Pair 2.
- The magnitude of the magnetic force is the same in both pairs.
- The magnitude of the magnetic force is greater in Pair 1.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material.

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.

Solution:
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.


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

Choices:
- The magnetic force is stronger in Pair 2.
- The strength of the magnetic force is the same in both pairs.
- The magnetic force is stronger in Pair 1.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material.

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 stronger the magnetic force between two magnets, the more strongly the magnets attract or repel each other.
You can change the strength of a magnetic force between two magnets by changing the distance between them. The magnetic force is stronger when the magnets are closer together.

Solution:
Distance affects the strength of the magnetic force. When magnets are closer together, the magnetic force between them is stronger.
The magnets in Pair 1 are closer together than the magnets in Pair 2. So, the magnetic force is stronger in Pair 1 than in Pair 2.


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

Choices:
- black racer
- gray fox
- silver maple
- black bear

Below is a food web from Shenandoah National Park, a forest ecosystem in Virginia.
A food web models how the matter eaten by organisms moves through an ecosystem. The arrows in a food web represent how matter moves between organisms in an ecosystem.

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.

Solution:
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 bear has an arrow pointing to it from the persimmon tree, which is a producer. The black bear also has arrows pointing to it from the swallowtail caterpillar and the beaver, which are consumers. The black bear eats a producer and consumers, so it is an omnivore.
The gray fox has two arrows pointing to it. These arrows start from the swallowtail caterpillar and the pine vole, which are both consumers.  So, the gray fox is a consumer but not an omnivore.
The pine vole has an arrow pointing to it from the persimmon tree, which is a producer. The pine vole also has an arrow pointing to it from the swallowtail caterpillar, which is a consumer. The pine vole eats a producer and a consumer, so it is an omnivore.
The silver maple does not have any arrows pointing to it. So, the silver maple is not an omnivore.
The black racer has only one arrow pointing to it. This arrow starts from the pine vole, which is a consumer. So, the black racer is a consumer but not an omnivore.


Question: Which property do these four objects have in common?

Choices:
- opaque
- fragile
- smooth

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.

Solution:
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 fragile object will break into pieces if you drop it. The ceramic mug is fragile, but the rock and the binder are not.
A smooth object is not scratchy or rough. The ceramic mug is smooth, but the rock are not.
The property that all four objects have in common is opaque.


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

Choices:
- The magnitude of the magnetic force is smaller in Pair 1.
- The magnitude of the magnetic force is smaller in Pair 2.
- The magnitude of the magnetic force is the same in both pairs.

The images below show two pairs of magnets. The magnets in different pairs do not affect each other. All the magnets shown are made of the same material, but some of them are different shapes.

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.

Solution:
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 2 than in Pair 1. So, the magnitude of the magnetic force is smaller in Pair 2 than in Pair 1.


Question: What can Reid and Daniel trade to each get what they want?

Choices:
- Reid can trade his tomatoes for Daniel's carrots.
- Daniel can trade his broccoli for Reid's oranges.
- Reid can trade his tomatoes for Daniel's broccoli.
- Daniel can trade his almonds for Reid's tomatoes.

Trade happens when people agree to exchange goods and services. People give up something to get something else. Sometimes people barter, or directly exchange one good or service for another.
Reid and Daniel open their lunch boxes in the school cafeteria. Neither Reid nor Daniel got everything that they wanted. The table below shows which items they each wanted:

Look at the images of their lunches. Then answer the question below.
Reid's lunch Daniel's lunch

social science

Solution:
Look at the table and images.
Reid wants broccoli. Daniel wants tomatoes. They can trade tomatoes for broccoli to both get what they want. Trading other things would not help both people get more items they want.


Question: Which property matches this object?

Choices:
- flexible
- fragile

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.

Solution:
Look at the object.
Think about each property.
A fragile object will break into pieces if you drop it. The ceramic mug is fragile.
A flexible object can be folded or bent without breaking easily. The ceramic mug is not flexible.


Question: Identify the question that Jeanette's experiment can best answer.

Choices:
- Do circuits that include iron produce dimmer light than circuits that include copper?
- Can light bulbs stay lit longer when circuits include copper or when circuits include iron?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Jeanette built an electric circuit: she used wires to connect a battery to a light bulb, the light bulb to a small piece of copper, and the copper back to the battery. When the circuit was complete, the light turned on. Jeanette observed the brightness of the light for five seconds. She then replaced the copper with a piece of iron of equal size and noted whether the light became brighter or dimmer. Jeanette built three more of the same type of circuit. She repeated the tests with each circuit. Jeanette recorded whether the circuits produced brighter light when the circuit included copper or when the circuit included iron.
Figure: a circuit with a battery, a light bulb, and a piece of copper.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question: Which property do these two objects have in common?

Choices:
- sour
- blue

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.

Solution:
Look at each object.
For each object, decide if it has that property.
Blue is a color.
This color is blue. Neither of the objects are blue.
A lemon has a sour taste. Both objects are sour.
The property that both objects have in common is sour.


Question: Identify the question that Wanda and Ernest's experiment can best answer.

Choices:
- Does Wanda's snowboard slide down a hill in less time when it has a thin layer of wax or a thick layer of wax?
- Does Wanda's snowboard slide down a hill in less time when it has a layer of wax or when it does not have a layer of wax?

The passage below describes an experiment. Read the passage and then follow the instructions below.

Wanda applied a thin layer of wax to the underside of her snowboard and rode the board straight down a hill. Then, she removed the wax and rode the snowboard straight down the hill again. She repeated the rides four more times, alternating whether she rode with a thin layer of wax on the board or not. Her friend Ernest timed each ride. Wanda and Ernest calculated the average time it took to slide straight down the hill on the snowboard with wax compared to the average time on the snowboard without wax.
Figure: snowboarding down a hill.

natural science

Experiments can be designed to answer specific questions. How can you identify the questions that a certain experiment can answer? In order to do this, you need to figure out what was tested and what was measured during the experiment.
Imagine an experiment with two groups of daffodil plants. One group of plants was grown in sandy soil, and the other was grown in clay soil. Then, the height of each plant was measured.
First, identify the part of the experiment that was tested. The part of an experiment that is tested usually involves the part of the experimental setup that is different or changed. In the experiment described above, each group of plants was grown in a different type of soil. So, the effect of growing plants in different soil types was tested.
Then, identify the part of the experiment that was measured. The part of the experiment that is measured may include measurements and calculations. In the experiment described above, the heights of the plants in each group were measured.
Experiments can answer questions about how the part of the experiment that is tested affects the part that is measured. So, the experiment described above can answer questions about how soil type affects plant height.
Examples of questions that this experiment can answer include:
Does soil type affect the height of daffodil plants?
Do daffodil plants in sandy soil grow taller than daffodil plants in clay soil?
Are daffodil plants grown in sandy soil shorter than daffodil plants grown in clay soil?


Question: What is the direction of this pull?

Choices:
- away from the sled dog team
- toward the sled dog team

A sled dog team moves a sled across the snow. The team uses a force to pull the sled forward.

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.

Solution: The dogs pull the sled. The direction of the pull is toward the sled dog team.


Question: Which state is highlighted?

Choices:
- Ohio
- South Dakota
- Nebraska
- Indiana

social science

Solution: This state is Indiana.


Question:
Complete the sentence.
Christianity and () originated in the same region of the world.

Choices:
- Buddhism
- Judaism
- Yoruba
- Hinduism

The following map shows where several major world religions originated, or began. Look at the map. Then complete the sentence below.

social science

Solution:
Look at the map.
The markers representing Christianity and Judaism are close together, so they originated in the same region of the world. Both religions started in the Middle East. In fact, Christianity actually started as a form of Judaism!
The other choices are not correct. Hinduism and Buddhism originated in present-day India, and Yoruba is an African religion that started near present-day Nigeria.


Question: Which continent is highlighted?

Choices:
- North America
- Europe
- Australia
- South America

social science

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

Solution: This continent is South America.


Question: Which bird's beak is also adapted to crack large, hard nuts?

Choices:
- African gray parrot
- white-tipped sicklebill

Scarlet macaws live in the forests of Central and South America. They eat large seeds and nuts. The shape of the 's beak is adapted to crack open large, hard nuts.
Figure: scarlet macaw.

natural science

Animal adaptations: beaks, mouths, and necks

An adaptation is an inherited trait that helps an organism survive or reproduce. Adaptations can include both body parts and behaviors.
The shape of a bird's beak is one example of an adaptation. Birds' beaks can be adapted in different ways. For example, a sharp hooked beak might help a bird tear through meat easily. A short, thick beak might help a bird break through a seed's hard shell. Birds that eat similar food often have similar beaks.

Solution:
Look at the picture of the scarlet macaw.
The scarlet macaw has a thick hooked beak. Its beak is adapted to crack large, hard nuts. The scarlet macaw uses its thick beak to crack the shell of a nut by squeezing it. The hooked shape of the beak can help the bird hold the nut in place while cracking it.
Now look at each bird. Figure out which bird has a similar adaptation.
The African gray parrot has a thick hooked beak. Its beak is adapted to crack large, hard nuts.
The white-tipped sicklebill has a long, thin, curved beak. Its beak is not adapted to crack large, hard nuts. The white-tipped sicklebill uses its beak to drink nectar out of long flowers.


Question: Which solution has a higher concentration of green particles?

Choices:
- Solution A
- neither; their concentrations are the same
- Solution B

The diagram below is a model of two solutions. Each green ball represents one particle of solute.

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

Solution:
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 B has more green particles per milliliter. So, Solution B has a higher concentration of green particles.


Question: What is the name of the colony shown?

Choices:
- Maryland
- New York
- Illinois
- Connecticut

social science

Solution: The colony is Maryland.


Question: What is the capital of New Jersey?

Choices:
- Augusta
- Montpelier
- Newark
- Trenton

social science

Identify state capitals of the Northeast

Solution: Trenton is the capital of New Jersey.


Question: What is the capital of New Mexico?

Choices:
- Albuquerque
- Santa Fe
- Carson City
- Lexington

social science

Solution: Santa Fe is the capital of New Mexico.


Question: Which trait did Palaeopython have? Select the trait you can observe on the fossil.

Choices:
- black stripes on its skin
- large fins on its body
- a long, thin body

This picture shows a fossil of an ancient animal called Palaeopython. Palaeopython lived in trees and could grow more than six feet long.

natural science

The way an organism looks or acts is called a trait. Scientists use fossils to learn more about the traits of ancient organisms.
Fossils can preserve the remains of body parts and activities. A fossil of a body part, such as a tail or a wing, can tell you what an organism looked like. A fossil of an organism's activities, such as a burrow or a footprint, can tell you about the organism's behavior.
Here are three examples of fossils and the traits that you can observe from them:
This is a fossil of an animal. This fossil tells you that the animal had a spiral-shaped shell.
This is a fossil of a plant. This fossil tells you that the plant had small leaves arranged in a branched pattern.
This is a fossil of an animal's footprint. This fossil tells you that the animal could walk on land.
An organism's fossil may not show all of the organism's traits. This is because most body parts are destroyed during fossil formation. When an organism's body turns into a fossil, only a few body parts are usually preserved.


Question: Is sphalerite a mineral?

Choices:
- no
- yes

Sphalerite has the following properties:
not made by living things
solid
pure substance
found in nature
fixed crystal structure

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.

Solution: Sphalerite has all the properties of a mineral. So, sphalerite is a mineral.


Question: Select the organism in the same species as the Eurasian beaver.

Choices:
- Castor fiber
- Ovis canadensis
- Lontra canadensis

This organism is a Eurasian beaver. Its scientific name is Castor fiber.

natural science

Use scientific names to classify organisms

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.

Solution:
A Eurasian beaver's scientific name is Castor fiber.
Ovis canadensis does not have the same scientific name as a Eurasian beaver. So, Castor fiber and Ovis canadensis are not in the same species.
Lontra canadensis does not have the same scientific name as a Eurasian beaver. So, Castor fiber and Lontra canadensis are not in the same species.
Castor fiber has the same scientific name as a Eurasian beaver. So, these organisms are in the same species.


Question: Select the organism in the same species as the snowy owl.

Choices:
- Bubo scandiacus
- Ardea herodias
- Pelecanus erythrorhynchos

This organism is a snowy owl. Its scientific name is Bubo scandiacus.

natural science

Use scientific names to classify organisms

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.

Solution:
A snowy owl's scientific name is Bubo scandiacus.
Bubo scandiacus has the same scientific name as a snowy owl. So, these organisms are in the same species.
Ardea herodias does not have the same scientific name as a snowy owl. So, Bubo scandiacus and Ardea herodias are not in the same species.
Pelecanus erythrorhynchos does not have the same scientific name as a snowy owl. So, Bubo scandiacus and Pelecanus erythrorhynchos are not in the same species.