Question: How do jumping spiders catch their food?

Choices:
- They catch bugs in a web.
- They jump onto bugs.
- They run fast to get bugs.

Read the first part of the passage about jumping spiders.
Jumping spiders are fast. They can also jump far.
Most spiders make webs to catch bugs. Then, they eat the bugs. But jumping spiders catch their food in another way. They jump onto flies and other bugs.

language science

Solution: The passage says that jumping spiders catch their food in a different way. They jump onto flies and other bugs.


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

Choices:
- if the spacecraft was damaged when using a parachute with a 1 m vent going 200 km per hour
- how steady a parachute with a 1 m vent was at 200 km per hour
- whether a parachute with a 1 m vent would swing too much at 400 km per hour

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.

Manny was an aerospace engineer who was developing a parachute for a spacecraft that would land on Mars. He needed to add a vent at the center of the parachute so the spacecraft would land smoothly. However, the spacecraft would have to travel at a high speed before landing. If the vent was too big or too small, the parachute might swing wildly at this speed. The movement could damage the spacecraft.
So, to help decide how big the vent should be, Manny put a parachute with a 1 m vent in a wind tunnel. The wind tunnel made it seem like the parachute was moving at 200 km per hour. He observed the parachute to see how much it swung.
Figure: a spacecraft's parachute in a wind tunnel.

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: Which of these states is farthest west?

Choices:
- Illinois
- Ohio
- Arkansas
- South Carolina

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 west arrow is pointing. Arkansas is farthest west.


Question: Which statement describes the Buffalo Gap National Grassland ecosystem?

Choices:
- It has heavy rain.
- It has a medium amount of rain.
- It has cold winters and cool summers.

Figure: Buffalo Gap National Grassland.
Buffalo Gap National Grassland is a prairie grassland ecosystem in southwestern South Dakota. It is home to the endangered black-footed ferret. This is the only kind of ferret that is native to North America.

natural science

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

Solution: A prairie grassland is a type of ecosystem. Prairie grasslands have the following features: hot summers and cool winters, a medium amount of rain, and soil that is rich in nutrients. So, the following statement describes the Buffalo Gap National Grassland ecosystem: hot summers and cool winters, a medium amount of rain, and soil that is rich in nutrients. It has a medium amount of rain. The following statements do not describe Buffalo Gap National Grassland: hot summers and cool winters, a medium amount of rain, and soil that is rich in nutrients. It has cold winters and cool summers. It has heavy rain.


Question: Look at the models of molecules below. Select the elementary substance.

Choices:
- acetaldehyde
- chloroform
- oxygen

natural science

Identify 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 boron is B, and the atomic symbol for the chemical element chlorine is Cl.
Scientists use different types of models to represent substances whose atoms are bonded in different ways. One type of model is a ball-and-stick model. The ball-and-stick model below represents a molecule of the compound boron trichloride.
In a ball-and-stick model, the balls represent atoms, and the sticks represent bonds. Notice that the balls in the model above are not all the same color. Each color represents a different chemical element. The legend shows the color and the atomic symbol for each chemical element in the substance.


Question:
Complete the statement.
Carbon tetrachloride is ().

Choices:
- an elementary substance
- a compound

The model below represents a molecule of carbon tetrachloride. Carbon tetrachloride was once used in fire extinguishers. It is no longer used because it is poisonous.

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 boron is B, and the atomic symbol for the chemical element chlorine is Cl.
Scientists use different types of models to represent substances whose atoms are bonded in different ways. One type of model is a ball-and-stick model. The ball-and-stick model below represents a molecule of the compound boron trichloride.
In a ball-and-stick model, the balls represent atoms, and the sticks represent bonds. Notice that the balls in the model above are not all the same color. Each color represents a different chemical element. The legend shows the color and the atomic symbol for each chemical element in the substance.

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


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

Choices:
- fragile
- bouncy
- hard

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.
A hard object does not change shape when pressed or squeezed. All three objects are hard.
A fragile object will break into pieces if you drop it. The diamond is not fragile.
A bouncy object will bounce back from the floor if you drop it. The fossil is not bouncy.
The property that all three objects have in common is hard.


Question: Which continent is highlighted?

Choices:
- Europe
- Africa
- Asia
- 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 Africa.


Question: Is quartz a mineral or a rock?

Choices:
- mineral
- rock

Quartz has the following properties:
solid
not made by living things
naturally occurring
white streak
fixed crystal structure
made of a pure substance called silica

natural science

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

Solution: Quartz has all the properties of a mineral. So, quartz is a mineral.


Question: Will these magnets attract or repel each other?

Choices:
- attract
- repel

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 north pole of the other magnet. Poles that are the same repel. So, these magnets will repel each other.


Question: Which of these continents does the prime meridian intersect?

Choices:
- Antarctica
- North America
- South America

social science

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

Solution: The prime meridian is the line at 0° longitude. It intersects Antarctica. It does not intersect South America or North America.


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

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

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 weaker when the magnets are farther apart.

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


Question: What is the name of the colony shown?

Choices:
- Virginia
- Florida
- South Carolina
- Maryland

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 Akira's test show?

Choices:
- how much the new turbine would weigh
- whether the new turbine could produce 10% more electricity
- if the new turbine could turn easily

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.

Wind turbines use wind power to produce electricity. Akira was a materials engineer who designed wind turbines. She wanted to design a new turbine that would produce 10% more electricity than older wind turbines. She thought that a turbine made from lightweight material would turn more easily and produce more electricity. So, Akira created a computer model of a turbine made from lightweight material. Then she used the model to calculate how much more electricity the new turbine could produce compared to the older turbines.
Figure: studying a wind turbine computer model.

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: Which animal's mouth is also adapted to eat plant matter?

Choices:
- zebra
- silky anteater

Cows are herbivores, or plant eaters. They eat grass and leaves. The 's mouth is adapted to grind up and eat plant matter.
Figure: cow.

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 cow.
The cow has long jaws and flat teeth. Its mouth is adapted to eat plant matter. The long jaws can help the cow reach leaves and grass. The flat teeth can help it cut and grind up the food into soft pieces it can swallow.
Now look at each animal. Figure out which animal has a similar adaptation.
The zebra has long jaws and flat teeth. Its mouth is adapted to eat plant matter.
The silky anteater has a long tube-shaped mouth and no teeth. Its mouth is not adapted to eat plant matter. The silky anteater uses its mouth to get insects out of holes and burrows.


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 south pole of one magnet is closest to the south pole of the other magnet. Like poles repel. So, these magnets will repel each other.


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

Choices:
- each vial . . . the surroundings
- the surroundings . . . each vial

Scientists in a laboratory were working with insulin, a protein often used to treat diabetes. They left two identical vials of insulin in different places. This table shows how the temperature of each vial changed over 15minutes.

natural science

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

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


Question: Which is this organism's common name?

Choices:
- marine file snake
- Acrochordus granulatus

This organism is a marine file snake. It is also called Acrochordus granulatus.

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:
Acrochordus granulatus is written in italics. The first word is capitalized, and the second word is not. So, it is the scientific name.
Acrochordus granulatus is the organism's scientific name. So, you know that marine file snake is the common name.


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.


Question: Will these magnets attract or repel each other?

Choices:
- attract
- repel

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 of the following best describes a community in the Southern Ocean?

Choices:
- the algae, the sea ice, and the seawater
- the Antarctic krill, the emperor penguins, and the leopard seals
- a pod of humpback whales

Read the passage. Then answer the question below.

Antarctic krill is a species of swimming crustacean, similar to shrimp, that is about 5 centimeters long. Krill eat the algae that grow on the underside of sea ice in the Southern Ocean around Antarctica.
Pods of humpback whales swim to the Southern Ocean every summer. Humpback whales and other animals, such as emperor penguins and leopard seals, eat Antarctic krill. In fact, Antarctic krill are eaten by almost every animal in Antarctica!
Figure: humpback whales in the Southern Ocean.

natural science

Describe populations, communities, and ecosystems

In an environment, organisms interact with each other and with their nonliving surroundings. To help describe these interactions, ecologists use specific terms for different types of groups.
A single organism is an individual. Individuals of the same species that live in the same place are part of a population.
Multiple populations of different species that live in the same place are part of a community.
Together, communities of living organisms and the nonliving parts of their environment make up an ecosystem.


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

Choices:
- transparent
- smooth
- flexible

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.
A flexible object can be folded or bent without breaking easily. The pool toy is flexible, but the ice hockey rink is not.
A smooth object is not scratchy or rough. All four objects are smooth.
You can see clearly through a transparent object. The bucket and the slide are not transparent.
The property that all four objects have in common is smooth.


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

Choices:
- long, thin antennae
- toes

This picture shows a fossil of an ancient animal called Meiolania. An adult Meiolania was about eight 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: What is the capital of Washington?

Choices:
- Spokane
- Olympia
- Springfield
- Seattle

social science

Solution: Olympia is the capital of Washington.


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

Choices:
- Mona can trade her almonds for Barry's tomatoes.
- Mona can trade her broccoli for Barry's oranges.
- Barry can trade his tomatoes for Mona's sandwich.
- Barry can trade his tomatoes for Mona'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.
Barry and Mona open their lunch boxes in the school cafeteria. Both of them could be happier with their lunches. Barry wanted broccoli in his lunch and Mona was hoping for tomatoes. Look at the images of their lunches. Then answer the question below.

social science

Solution:
Barry wanted broccoli in his lunch and Mona was hoping for tomatoes. Look at the labeled part of the images.
Barry has tomatoes. Mona 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: What is the capital of Maine?

Choices:
- Portland
- Hartford
- Augusta
- Athens

social science

Identify state capitals of the Northeast

Solution: Augusta is the capital of Maine.


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

Choices:
- whether an inexpensive filter would become clogged more often
- whether the filter was clogged
- the amount of bacteria in the water before it was filtered

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.

Darnell was . At the plant, an expensive filter was used to remove disease-causing bacteria from the water. But over time, the filter would become clogged with bacteria. If the filter became clogged, the water would not move through quickly enough. Darnell had to decide when the filter was too clogged and needed to be replaced. So, during his inspection, Darnell checked the filter by measuring how quickly water moved through it.
Figure: an engineer at a water treatment plant.

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: Which continent is highlighted?

Choices:
- North America
- Australia
- Antarctica
- 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 Australia.


Question: Which country is highlighted?

Choices:
- Kiribati
- Nauru
- the Federated States of Micronesia
- the Marshall Islands

social science

Identify and select countries of Oceania

Solution:
This country is the Marshall Islands.
Does the Marshall Islands have any territorial disputes?
The Marshall Islands claims to own Wake Island, which is a disputed territory. In other words, multiple countries or groups claim that the area rightfully belongs to them.
The United States claimed Wake Island in 1899 and has controlled it since then. But the Marshall Islands considers the island part of its territory. It says that its people have traveled to the island to gather food and resources for many years. Today, the island is mainly used by the U.S. Air Force.


Question: What is the capital of Montana?

Choices:
- Helena
- Carson City
- Nampa
- Boise

social science

Solution: Helena is the capital of Montana.


Question: In this food chain, the brown trout is a secondary consumer. Why?

Choices:
- It eats a secondary consumer.
- It eats a primary consumer.
- It eats a producer.

This diagram shows a food chain from the River Frome, a freshwater ecosystem in England.

natural science

Every organism needs food to stay alive. Organisms get their food in different ways. A food chain shows how organisms in an ecosystem get their food.
The food chain begins with the producer. A producer can change matter that is not food into food. Many producers use carbon dioxide, water, and sunlight to make sugar. Carbon dioxide and water are not food, but sugar is food for the producer.
Consumers eat other organisms. There can be several kinds of consumers in a food chain:
A primary consumer eats producers. The word primary tells you that this is the first consumer in a food chain.
A secondary consumer eats primary consumers. The word secondary tells you that this is the second consumer in a food chain.
A tertiary consumer eats secondary consumers. The word tertiary tells you that this is the third consumer in a food chain.
A top consumer is the animal at the top of a food chain. Food chains can have different numbers of organisms. For example, when there are four organisms in the chain, the top consumer is the tertiary consumer. But if there are five organisms in the chain, the top consumer eats the tertiary consumer!

Solution: In this food chain, the brown trout is a secondary consumer because it eats a primary consumer. The primary consumer in this food chain is the midge larva.


Question: What is the capital of Utah?

Choices:
- Denver
- Provo
- Salt Lake City
- Orlando

social science

Solution: Salt Lake City is the capital of Utah.


Question: Which animal's skin is also adapted for survival in cold places?

Choices:
- naked mole rat
- snowy owl

Caribou live in Canada and the northern United States. The 's skin is adapted to help the animal survive in cold places.
Figure: caribou.

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 caribou.
During the winter, the caribou has thick fur covering its skin. Its skin is adapted for survival in cold places. The caribou uses its fur to keep warm in cold weather.
Now look at each animal. Figure out which animal has a similar adaptation.
The snowy owl has a thick coat of feathers covering its skin. Its skin is adapted for survival in cold places.
The naked mole rat has thin skin covering its body. Its skin is not adapted for survival in cold places.


Question: What is the capital of Alaska?

Choices:
- Bismarck
- Juneau
- Nampa
- Santa Fe

social science

Solution: Juneau is the capital of Alaska.


Question: Which is this organism's common name?

Choices:
- great white shark
- Carcharodon carcharias

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

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, it is the scientific name.
Carcharodon carcharias is the organism's scientific name. So, you know that great white shark is the common name.


Question: What is the capital of Nevada?

Choices:
- Reno
- Carson City
- Olympia
- Austin

social science

Solution: Carson City is the capital of Nevada.


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

Choices:
- feather
- ginkgo leaf

This diagram shows fossils in an undisturbed sedimentary rock sequence.

natural science

Compare ages of fossils in a rock sequence

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

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


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

Choices:
- neither; their concentrations are the same
- Solution A
- 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 A has more green particles per milliliter. So, Solution A has a higher concentration of green particles.


Question: Which material is this spatula made of?

Choices:
- cotton
- wood

natural science

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

Solution:
Look at the picture of the spatula.
The spatula is made of two different materials. The handle is made of wood, and the head is made of rubber.


Question: Which animal's skin is also adapted for survival in cold places?

Choices:
- Amazon milk frog
- Eurasian lynx

Arctic wolves live in the Canadian Arctic and Greenland. The 's skin is adapted to help the animal survive in cold places.
Figure: Arctic wolf.

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 Arctic wolf.
The Arctic wolf has thick fur covering its skin. Its skin is adapted for survival in cold places. The Arctic wolf uses its fur to keep warm in cold weather.
Now look at each animal. Figure out which animal has a similar adaptation.
During the winter, the Eurasian lynx has thick fur covering its skin. Its skin is adapted for survival in cold places.
The Amazon milk frog has thin, moist skin. Its skin is not adapted for survival in cold places.


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

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 2 are closer together than the magnets in Pair 1. So, the magnetic force is stronger in Pair 2 than in Pair 1.


Question: What is the expected ratio of offspring with a gray body to offspring with a golden body? Choose the most likely ratio.

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

In a group of guppies, some individuals have a gray body and others have a golden body. In this group, the gene for the body color trait has two alleles. The allele for a golden body (b) is recessive to the allele for a gray body (B).
This Punnett square shows a cross between two guppies.

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 gray body or a golden body, consider whether each phenotype is the dominant or recessive allele's version of the body color trait. The question tells you that the b allele, which is for a golden body, is recessive to the B allele, which is for a gray body.
A gray body is the dominant allele's version of the body color trait. A guppy with the dominant version of the body color trait must have at least one dominant allele for the body color gene. So, offspring with a gray body must have the genotype BB or Bb.
There are 3 boxes in the Punnett square with the genotype BB or Bb. These boxes are highlighted below.
A golden body is the recessive allele's version of the body color trait. A guppy with the recessive version of the body color trait must have only recessive alleles for the body color gene. So, offspring with a golden body must have the genotype bb.
There is 1 box in the Punnett square with the genotype bb. This box is highlighted below.
So, the expected ratio of offspring with a gray body to offspring with a golden body is 3:1. This means that, on average, this cross will produce 3 offspring with a gray body for every 1 offspring with a golden body.


Question: Which fish's mouth is also adapted for tearing through meat?

Choices:
- seahorse
- starry moray

Barracudas often hunt large fish for food. The 's mouth is adapted to tear through meat.
Figure: barracuda.

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 barracuda.
The barracuda has a large mouth and sharp teeth. Its mouth is adapted for tearing through meat. The baracuda uses its teeth to cut up meat into pieces it can swallow.
Now look at each animal. Figure out which animal has a similar adaptation.
The starry moray has a large mouth and sharp teeth. Its mouth is adapted for tearing through meat.
The seahorse a long, narrow mouth. Its mouth is not adapted for tearing through meat.


Question: Which statement describes the Catoctin Mountain Park ecosystem?

Choices:
- It has many different types of trees.
- It has soil that is rich in nutrients.

Figure: Catoctin Mountain Park.
Catoctin Mountain Park is a temperate deciduous forest ecosystem in Maryland. Most of this forest was cut down for its wood in the early 1900s. But since the 1940s, conservation efforts have allowed the forest to return to much of this park.

natural science

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

Solution: A temperate deciduous forest is a type of ecosystem. Temperate deciduous forests have the following features: warm, wet summers and cold, wet winters, soil that is rich in nutrients, and only a few types of trees. So, the following statements describe the Catoctin Mountain Park ecosystem: warm, wet summers and cold, wet winters, soil that is rich in nutrients, and only a few types of trees. It has warm, wet summers and cold, wet winters. It has soil that is rich in nutrients. The following statement does not describe Catoctin Mountain Park: warm, wet summers and cold, wet winters, soil that is rich in nutrients, and only a few types of trees. It has many different types of trees.


Question: Which of these states is farthest north?

Choices:
- Utah
- Minnesota
- Kentucky
- Mississippi

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 north arrow is pointing. Minnesota is farthest north.


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

Choices:
- fragile
- stretchy
- sour

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.
A fragile object will break into pieces if you drop it. The rubber band is not fragile.
A stretchy object gets longer when you pull on it. All four objects are stretchy.
A lemon has a sour taste. The melted marshmallow is not sour.
The property that all four objects have in common is stretchy.


Question: Is Nerium oleander made up of one cell?

Choices:
- no
- yes

This organism is Nerium oleander. It is a member of the plant kingdom.
Nerium oleander is commonly called an oleander plant. Oleander plants are toxic to many animals. Oleander plants contain a poison that can make animals sick. This poison helps protect oleander plants from being eaten by animals.

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: Nerium oleander is a plant. Plants are made up of many cells.


Question: Which statement describes the Kaeng Krachan National Park ecosystem?

Choices:
- It has many different types of organisms.
- It has mostly small plants.
- It has soil that is rich in nutrients.

Figure: Kaeng Krachan National Park.
Kaeng Krachan National Park is a tropical rain forest ecosystem in western Thailand. It is Thailand's largest national park and has many animals, including elephants.

natural science

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

Solution: A tropical rain forest is a type of ecosystem. Tropical rain forests have the following features: year-round rain and warm temperatures, soil that is poor in nutrients, and many different types of organisms. So, the following statement describes the Kaeng Krachan National Park ecosystem: year-round rain and warm temperatures, soil that is poor in nutrients, and many different types of organisms. It has many different types of organisms. The following statements do not describe Kaeng Krachan National Park: year-round rain and warm temperatures, soil that is poor in nutrients, and many different types of organisms. It has soil that is rich in nutrients. It has mostly small plants.


Question: What is the capital of Nevada?

Choices:
- Reno
- Las Vegas
- Carson City
- Bismarck

social science

Solution: Carson City is the capital of Nevada.


Question: Which of these states is farthest east?

Choices:
- New Mexico
- Ohio
- New Hampshire
- Delaware

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. New Hampshire is farthest east.


Question: What is the capital of Alaska?

Choices:
- Juneau
- Boston
- Fairbanks
- Honolulu

social science

Solution: Juneau is the capital of Alaska.


Question: What is the capital of Louisiana?

Choices:
- Baton Rouge
- Anchorage
- Charleston
- Juneau

social science

Identify state capitals of the Southeast

Solution: Baton Rouge is the capital of Louisiana.


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:
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 of these states is farthest north?

Choices:
- Arizona
- Mississippi
- Oklahoma
- Wyoming

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 north arrow is pointing. Wyoming is farthest north.


Question: Which of these organisms contains matter that was once part of the bilberry?

Choices:
- collared lemming
- earthworm
- lichen
- bear sedge

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:
Use the arrows to follow how matter moves through this food web. For each answer choice, try to find a path of arrows that starts from the bilberry.
No arrow points to the lichen. So, in this food web, matter does not move from the bilberry to the lichen.
No arrow points to the bear sedge. So, in this food web, matter does not move from the bilberry to the bear sedge.
There are two arrows pointing to the collared lemming. One arrow starts from the bear sedge, and the other arrow starts from the lichen. Neither the bear sedge nor the lichen has an arrow pointing to it. So, in this food web, matter does not move from the bilberry to the collared lemming.


Question: What is the capital of Nevada?

Choices:
- Boise
- Pierre
- Carson City
- Portland

social science

Solution: Carson City is the capital of Nevada.


Question: What is the probability that a cockatiel produced by this cross will have bright orange cheeks?

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

In a group of cockatiels, some individuals have bright orange cheeks and others have pale orange cheeks. In this group, the gene for the cheek color trait has two alleles. The allele for bright orange cheeks (R) is dominant over the allele for pale orange cheeks (r).
This Punnett square shows a cross between two cockatiels.

natural science

Use Punnett squares to calculate probabilities 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.
In a Punnett square, each box represents a different outcome, or result. Each of the four outcomes is equally likely to happen. Each box represents one way the parents' alleles can combine to form an offspring's genotype. Because there are four boxes in the Punnett square, there are four possible outcomes.
An event is a set of one or more outcomes. The probability of an event is a measure of how likely the event is to happen. This probability is a number between 0 and 1, and it can be written as a fraction:
probability of an event = number of ways the event can happen / number of equally likely outcomes
You can use a Punnett square to calculate the probability that a cross will produce certain offspring. For example, the Punnett square below has two boxes with the genotype Ff. It has one box with the genotype FF and one box with the genotype ff. This means there are two ways the parents' alleles can combine to form Ff. There is one way they can combine to form FF and one way they can combine to form ff.
 | F | f
F | FF | Ff
f | Ff | ff
Consider an event in which this cross produces an offspring with the genotype ff. The probability of this event is given by the following fraction:
number of ways the event can happen / number of equally likely outcomes = number of boxes with the genotype ff / total number of boxes = 1 / 4.


Question: What is the name of the colony shown?

Choices:
- Virginia
- New Jersey
- Kentucky
- Massachusetts

social science

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


Question: What is the capital of Connecticut?

Choices:
- Hartford
- Burlington
- Boston
- Harrisburg

social science

Identify state capitals of the Northeast

Solution: Hartford is the capital of Connecticut.


Question: Which term matches the picture?

Choices:
- endoskeleton
- exoskeleton

Read the text.
All animals that live on land have some sort of skeletal system. Some animals have what is called an endoskeleton. They have a system of connected bones inside their bodies. This skeleton grows as the animal grows. This helps to support a larger body. Other animals have what is called an exoskeleton. An exoskeleton is a hard covering on the outside of an animal's body. Exoskeletons do not change size, so they must be shed and replaced as an animal grows.

language science

Determine the meaning of domain-specific words with pictures

Solution: An exoskeleton is a skeleton that is outside of an animal's body. Insects, like dragonflies, have exoskeletons. When they grow, they molt and shed their exoskeletons.


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.

Solution:
Both magnet sizes and distance affect the magnitude of the magnetic force. The sizes of the magnets in Pair 1 are the same as in Pair 2. The distance between the magnets is also the same.
So, the magnitude of the magnetic force is the same in both pairs.


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

Choices:
- The magnetic force is weaker in Pair 2.
- The magnetic force is weaker in Pair 1.
- The strength 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.

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.

Solution:
Distance affects the strength of the magnetic force. But the distance between the magnets in Pair 1 and in Pair 2 is the same.
So, the strength of the magnetic force is the same in both pairs.


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

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

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 weaker when the magnets are farther apart.

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


Question: Which of these states is farthest west?

Choices:
- Virginia
- Rhode Island
- Mississippi
- Minnesota

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 west arrow is pointing. Minnesota is farthest west.


Question: Select the mammal below.

Choices:
- red howler
- box turtle
- flamingo
- cassowary

Mammals have hair or fur and feed their young milk.
Mammals are warm-blooded. Warm-blooded animals can control their body temperature.
A gray wolf is an example of a mammal.

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 box turtle is a reptile. It has scaly, waterproof skin.
Box turtles can live to be over 100 years old!
A red howler is a mammal. It has hair and feeds its young milk.
Howler monkeys have loud calls, or howls. Their calls can be heard over three miles away!
A flamingo is a bird. It has feathers, two wings, and a beak.
Flamingos live in large groups. These groups are called flocks.
A cassowary is a bird. It has feathers, two wings, and a beak.
Cassowaries have wings, but they cannot fly! They can run very fast.


Question: What is the capital of Washington?

Choices:
- Olympia
- Seattle
- Spokane
- Topeka

social science

Solution: Olympia is the capital of Washington.


Question: Look at the models of molecules below. Select the elementary substance.

Choices:
- fluoromethanol
- dichloromethane
- chlorine

natural science

Identify 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 boron is B, and the atomic symbol for the chemical element chlorine is Cl.
Scientists use different types of models to represent substances whose atoms are bonded in different ways. One type of model is a ball-and-stick model. The ball-and-stick model below represents a molecule of the compound boron trichloride.
In a ball-and-stick model, the balls represent atoms, and the sticks represent bonds. Notice that the balls in the model above are not all the same color. Each color represents a different chemical element. The legend shows the color and the atomic symbol for each chemical element in the substance.


Question: What is the capital of Wisconsin?

Choices:
- Madison
- Green Bay
- Milwaukee
- Jefferson City

social science

Solution: Madison is the capital of Wisconsin.


Question: Which letter marks ancient Egypt?

Choices:
- B
- C
- D
- A

Ancient Egypt was one of the first civilizations. Civilizations are complex societies with organized communities and governments. Many of the first civilizations started around big rivers. Look at the map of early river civilizations. Then answer the question below.

social science

Solution:
Look at the map. It labels ancient Egypt and other ancient civilizations.
Ancient Egyptian civilization started along the Nile River. Other ancient civilizations also started near rivers. For example, ancient Mesopotamian civilizations started along the Tigris and Euphrates Rivers, ancient Indus Valley civilizations started along the Indus River, and ancient Chinese civilization began between the Yellow and Yangtze Rivers.


Question: What is the capital of Florida?

Choices:
- Richmond
- Minneapolis
- Tallahassee
- Orlando

social science

Identify state capitals of the Southeast

Solution: Tallahassee is the capital of Florida.


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

Choices:
- the surroundings . . . each refrigerator
- each refrigerator . . . the surroundings

Two identical refrigerators in a restaurant kitchen lost power. The door of one fridge was slightly open, and the door of the other fridge was closed. This table shows how the temperature of each refrigerator changed over 10minutes.

natural science

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

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


Question: Which is this organism's scientific name?

Choices:
- diving beetle
- Cybister sugillatus

This organism is a diving beetle. It is also called Cybister sugillatus.

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:
Cybister sugillatus is written in italics. The first word is capitalized, and the second word is not.
So, Cybister sugillatus is the scientific name.


Question: Which of the following statements is true?

Choices:
- Each bryum moss cell is over 0.37 millimeters long.
- The organism shown in the micrograph is made up of cells, but the organism in the photograph is not.
- Bryum moss plants are made up of tiny units called cells.

Look at the images and read the text. Then, answer the question.

Figure 1: a photograph of bryum moss.
This image is a photograph of a plant called bryum moss. The photograph was taken with an ordinary camera. It shows what you would see if you looked at bryum moss closely.

Figure 2: a micrograph of bryum moss.
This image also shows bryum moss. The image is a micrograph, which is a magnified picture taken with the aid of a microscope. The magnified image shows a section of the plant that is only 0.37 millimeters long!
The micrograph shows that the plant is made up of small, similarly shaped units. In this image, each unit looks like it has six sides and is surrounded by a white border. These units are called cells.

natural science


Question: What is the name of the colony shown?

Choices:
- Illinois
- New Jersey
- Tennessee
- Maryland

social science

Solution: The colony is New Jersey.


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 2.
- The magnitude of the magnetic force is the same in both pairs.
- The magnitude of the magnetic force is smaller 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, but some of them are different sizes.

natural science

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

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


Question: What is the capital of Alabama?

Choices:
- Jefferson City
- Wichita
- Oklahoma City
- Montgomery

social science

Identify state capitals of the Southeast

Solution: Montgomery is the capital of Alabama.


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

Choices:
- stretchy
- hard
- 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. Grouping objects by their properties is called classification.

Solution:
Look at each object.
For each object, decide if it has that property.
A hard object does not change shape when pressed or squeezed. None of the objects are hard.
A stretchy object gets longer when you pull on it. All three objects are stretchy.
A fragile object will break into pieces if you drop it. None of the objects are fragile.
The property that all three objects have in common is stretchy.


Question: Which property matches this object?

Choices:
- rough
- soft

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 soft object changes shape when pressed or squeezed. The apron is soft.
A rough object feels scratchy when you touch it. The apron is not rough.


Question: What is the probability that a rose plant produced by this cross will have dark yellow flowers?

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

In a group of rose plants, some individuals have light yellow flowers and others have dark yellow flowers. In this group, the gene for the flower color trait has two alleles. The allele for light yellow flowers (F) is dominant over the allele for dark yellow flowers (f).
This Punnett square shows a cross between two rose plants.

natural science

Use Punnett squares to calculate probabilities 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.
In a Punnett square, each box represents a different outcome, or result. Each of the four outcomes is equally likely to happen. Each box represents one way the parents' alleles can combine to form an offspring's genotype. Because there are four boxes in the Punnett square, there are four possible outcomes.
An event is a set of one or more outcomes. The probability of an event is a measure of how likely the event is to happen. This probability is a number between 0 and 1, and it can be written as a fraction:
probability of an event = number of ways the event can happen / number of equally likely outcomes
You can use a Punnett square to calculate the probability that a cross will produce certain offspring. For example, the Punnett square below has two boxes with the genotype Ff. It has one box with the genotype FF and one box with the genotype ff. This means there are two ways the parents' alleles can combine to form Ff. There is one way they can combine to form FF and one way they can combine to form ff.
 | F | f
F | FF | Ff
f | Ff | ff
Consider an event in which this cross produces an offspring with the genotype ff. The probability of this event is given by the following fraction:
number of ways the event can happen / number of equally likely outcomes = number of boxes with the genotype ff / total number of boxes = 1 / 4.


Question: Is an empty cup a solid or a liquid?

Choices:
- a solid
- a liquid

natural science

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

Solution:
An empty cup is a solid. A solid has a size and shape of its own.
When you fill a cup with water, the cup still has its own shape.


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

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

Choices:
- Tallahassee
- Carson City
- Phoenix
- Juneau

social science

Solution: Carson City is the capital of Nevada.


Question: What is the name of the colony shown?

Choices:
- Rhode Island
- South Carolina
- Pennsylvania
- Tennessee

social science

Solution: The colony is Pennsylvania.


Question: Identify the question that Ashley'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.

Ashley 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. Ashley 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. Ashley built three more of the same type of circuit. She repeated the tests with each circuit. Ashley 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: Is chalk a solid or a liquid?

Choices:
- a solid
- a liquid

natural science

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

Solution: Chalk is a solid. You can easily break chalk into pieces. But each piece will still have a size and shape of its own.


Question: Which of these states is farthest south?

Choices:
- Maine
- Virginia
- Arkansas
- 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. Arkansas is farthest south.


Question: What is the capital of Arizona?

Choices:
- Phoenix
- Baton Rouge
- Fort Wayne
- Juneau

social science

Solution: Phoenix is the capital of Arizona.


Question: What can a pine seed grow into?

Choices:
- a female cone
- a new plant
- a male cone

natural science

Describe and construct conifer life cycles

Conifers are plants that grow cones. Conifers use their cones to reproduce, or make new plants like themselves. How do conifers use their cones to reproduce?
Conifers can grow male and female cones. Male cones make pollen, and female cones make eggs. Pollination is what happens when wind blows pollen from male cones onto female cones. After pollination, sperm from the pollen can combine with eggs. This is called fertilization. The fertilized eggs grow into seeds.
The seeds can fall out of the cones and land on the ground. When a seed lands on the ground, it can germinate, or start to grow into a new plant.

Solution:
A seed can germinate and grow into a new plant.
The new plant can grow male and female cones. But a seed does not grow into a male cone or a female cone.


Question: Select the mammal below.

Choices:
- barn owl
- sea otter

Mammals have hair or fur and feed their young milk. A giraffe is an example of a mammal.

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 sea otter is a mammal. It has fur and feeds its young milk.
A barn owl is a bird. It has feathers, two wings, and a beak.


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

Choices:
- bumpy
- bouncy
- shiny

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 bouncy object will bounce back from the floor if you drop it. The popcorn and the tree bark are not bouncy.
A shiny object reflects a lot of light. You can usually see your reflection in a shiny object. None of the objects are shiny.
A bumpy object is covered in lumps and bumps. All three objects are bumpy.
The property that all three objects have in common is bumpy.


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

Choices:
- stretchy
- shiny
- 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.
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.
A stretchy object gets longer when you pull on it. All four objects are stretchy.
You can see clearly through a transparent object. None of the objects are transparent.
A shiny object reflects a lot of light. You can usually see your reflection in a shiny object. The wool hat is not shiny.
The property that all four objects have in common is stretchy.


Question: Which better describes the Pantanal ecosystem?

Choices:
- It has soil that is poor in nutrients. It also has only a few types of organisms.
- It has land that is covered with water during most of the year. It also has soil that is rich in nutrients.

Figure: Pantanal.
The Pantanal is a wetland ecosystem located mostly in Brazil.

natural science

An ecosystem is formed when living and nonliving things interact in an environment. There are many types of ecosystems. Here are some ways in which ecosystems can differ from each other:
the pattern of weather, or climate
the type of soil or water
the organisms that live there

Solution: A wetland is a type of ecosystem. Wetlands have the following features: land that is covered with water during most of the year, soil that is rich in nutrients, and other water ecosystems nearby. So, the Pantanal has land that is covered with water during most of the year. It also has soil that is rich in nutrients.


Question: Which continent is highlighted?

Choices:
- Africa
- North America
- 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 Africa.


Question: What is the capital of Montana?

Choices:
- Plymouth
- Boise
- Helena
- Billings

social science

Solution: Helena is the capital of Montana.


Question: Will these magnets attract or repel each other?

Choices:
- attract
- repel

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: Which state is highlighted?

Choices:
- Texas
- Oklahoma
- Virginia
- Georgia

social science

Solution: This state is Virginia.


Question: Which part of the tomato plant makes the seeds?

Choices:
- the fruit
- the flowers

natural science

Describe and construct flowering plant life cycles

Many plants have flowers. These plants can use their flowers to reproduce, or make new plants like themselves. How do plants use their flowers to reproduce?
First, the male part of the flower makes pollen, and the female part makes eggs. Animals, wind, or water can move pollen. Pollination is what happens when pollen is moved to the female part of the flower.
After pollination, sperm from the pollen can combine with the eggs. This is called fertilization. The fertilized eggs grow into seeds. The fruit grows around the seeds. Later, a seed can fall out of the fruit. It can germinate, or start to grow into a new plant.

Solution:
Flowers make seeds. After a flower is pollinated, male cells from the pollen combine with eggs. This is called fertilization. The fertilized eggs grow into seeds.
The fruit can grow around the seeds. But the fruit does not make seeds. Both the fruit and the seeds grow from parts of the flower.


Question: Select the mammal below.

Choices:
- painted stork
- red kangaroo

Mammals have hair or fur and feed their young milk. A human is an example of a mammal.

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 painted stork is a bird. It has feathers, two wings, and a beak.
Storks wade in shallow water to look for food. Storks eat fish, insects, worms, and other small animals.
A red kangaroo is a mammal. It has fur and feeds its young milk.
Kangaroos hop to move around. They use their large tails for balance while hopping.


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

Choices:
- if at least 20% of the park would be shaded by trees in each design
- which design would have the greatest distance between the concert area and the road
- which design would have the least traffic noise in the concert area

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.

Kenny was a landscape architect who was hired to design a new city park. The city council wanted the park to have space for outdoor concerts and to have at least 20% of the park shaded by trees. Kenny thought the concert area should be at least 150 meters from the road so traffic noise didn't interrupt the music. He developed three possible designs for the park with the concert area in a different location in each design. Then, he tested each design by measuring the distance between the road and the concert area.
Figure: studying an architect's design.

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: In this food chain, the amphipod is a consumer. Why?

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

This diagram shows a food chain from Lake Superior, a freshwater ecosystem on the border of the United States and Canada.

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 amphipod is a consumer because it eats another living thing. The amphipod in this food chain eats the algae.


Question: Select the organism in the same genus as the palmate newt.

Choices:
- Taricha torosa
- Ambystoma opacum
- Lissotriton vulgaris

This organism is a palmate newt. Its scientific name is Lissotriton helveticus.

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 palmate newt's scientific name is Lissotriton helveticus. The first word of its scientific name is Lissotriton.
Lissotriton vulgaris is in the genus Lissotriton. The first word of its scientific name is Lissotriton. So, Lissotriton vulgaris and Lissotriton helveticus are in the same genus.
Taricha torosa is in the genus Taricha. The first word of its scientific name is Taricha. So, Taricha torosa and Lissotriton helveticus are not in the same genus.
Ambystoma opacum is in the genus Ambystoma. The first word of its scientific name is Ambystoma. So, Ambystoma opacum and Lissotriton helveticus are not in the same genus.