Question: Which of these states is farthest west?

Choices:
- Delaware
- Idaho
- Georgia
- Arkansas

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. Idaho is farthest west.


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

Choices:
- hard
- soft

natural science

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

Solution:
Look at each object.
For each object, decide if it has that property.
A soft object changes shape when you squeeze it. Neither of the objects are soft.
A hard object keeps its shape when you squeeze it. Both objects are hard.
The property that both objects have in common is hard.


Question: What is the capital of Indiana?

Choices:
- Columbus
- Indianapolis
- Fort Wayne
- Lansing

social science

Solution: Indianapolis is the capital of Indiana.


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

Choices:
- The riverbed is dry and cracked.
- The ground is mostly flat.

This picture was taken during a drought. A drought happens when an area gets less rain or snow than usual.

natural science

Find evidence of changes to Earth's surface

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


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

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

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

natural science

Identify how particle motion affects temperature and pressure

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

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


Question: Which better describes the Gunung Leuser National Park ecosystem?

Choices:
- It has year-round warm temperatures. It also has soil that is poor in nutrients.
- It has cold winters. It also has soil that is rich in nutrients.

Figure: Gunung Leuser National Park.
Gunung Leuser National Park is a tropical rain forest ecosystem in Sumatra, an island in western Indonesia.

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, Gunung Leuser National Park has year-round warm temperatures. It also has soil that is poor in nutrients.


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

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

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

natural science

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

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


Question: Which better describes the Taklamakan Desert ecosystem?

Choices:
- It has dry, thin soil. It also has a small amount of rain or snow.
- It has heavy snow. It also has only a few types of trees.

Figure: Taklamakan Desert.
The Taklamakan Desert is a cold desert ecosystem in northwestern China.

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


Question: What is the name of the colony shown?

Choices:
- Georgia
- Rhode Island
- Pennsylvania
- Iowa

social science

Solution: The colony is Pennsylvania.


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: What is the capital of Arkansas?

Choices:
- Little Rock
- Fayetteville
- Tallahassee
- Arlington

social science

Identify state capitals of the Southeast

Solution: Little Rock is the capital of Arkansas.


Question: Which of these states is farthest north?

Choices:
- Missouri
- North Carolina
- Arizona
- Texas

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. Missouri is farthest north.


Question: What can Jasmine and Bryan trade to each get what they want?

Choices:
- Jasmine can trade her tomatoes for Bryan's carrots.
- Bryan can trade his broccoli for Jasmine's oranges.
- Bryan can trade his almonds for Jasmine's tomatoes.
- Jasmine can trade her tomatoes for Bryan'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.
Jasmine and Bryan open their lunch boxes in the school cafeteria. Neither Jasmine nor Bryan got everything that they wanted. The table below shows which items they each wanted:

Look at the images of their lunches. Then answer the question below.
Jasmine's lunch Bryan's lunch

social science

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


Question: Which animal's feet are also adapted for swimming?

Choices:
- giraffe
- African clawed frog

The  is found in rivers and streams in South America. It eats small fish, worms, and crustaceans, which it often finds underwater. Its feet are adapted for swimming.
Figure: Suriname toad.

natural science

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

Solution:
Look at the picture of the Suriname toad.
The Suriname toad has webbed feet. Its feet are adapted for swimming. As it swims, the Suriname toad uses its webbed feet to push itself through water.
Now look at each animal. Figure out which animal has a similar adaptation.
The African clawed frog has webbed feet. Its feet are adapted for swimming.
The giraffe has large, heavy, hoofed feet. Its feet are not adapted for swimming. The giraffe uses its feet to walk and run on hard ground.


Question: What is the capital of Texas?

Choices:
- Rapid City
- Charleston
- Austin
- Dallas

social science

Identify state capitals of the Southeast

Solution: Austin is the capital of Texas.


Question: Select the organism in the same species as the Chinese mitten crab.

Choices:
- Melanoplus bivittatus
- Acanthaster planci
- Eriocheir sinensis

This organism is a Chinese mitten crab. Its scientific name is Eriocheir sinensis.

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 Chinese mitten crab's scientific name is Eriocheir sinensis.
Eriocheir sinensis has the same scientific name as a Chinese mitten crab. So, these organisms are in the same species.
Acanthaster planci does not have the same scientific name as a Chinese mitten crab. So, Eriocheir sinensis and Acanthaster planci are not in the same species.
Melanoplus bivittatus does not have the same scientific name as a Chinese mitten crab. So, Eriocheir sinensis and Melanoplus bivittatus are not in the same species.


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

Choices:
- barren-ground caribou
- bilberry

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 to the earthworm.
Arrows point from the barren-ground caribou to the grizzly bear and the mushroom. The only arrow pointing from the grizzly bear leads to the mushroom. No arrows point from the mushroom to any other organisms. So, in this food web, matter does not move from the barren-ground caribou to the earthworm.


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

Choices:
- each aquarium . . . the surroundings
- the surroundings . . . each aquarium

Two identical aquariums were next to an open window. One aquarium had a plastic cover on it, and the other was uncovered. This table shows how the temperature of each aquarium changed over 1.5hours.

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 aquarium decreased, which means that the thermal energy of each aquarium decreased. So, thermal energy was transferred from each aquarium to the surroundings.


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

Choices:
- breakable
- rough

natural science

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

Solution:
Look at each object.
For each object, decide if it has that property.
A rough object feels scratchy when you touch it. Neither of the objects are rough.
A breakable object will break into pieces if you drop it. Both objects are breakable.
The property that both objects have in common is breakable.


Question: Which statement describes the Kibale National Forest ecosystem?

Choices:
- It has soil that is poor in nutrients.
- It has soil that is rich in nutrients.

Figure: Kibale National Forest.
Kibale National Forest is a tropical rain forest ecosystem in Uganda, a country in eastern Africa. This rain forest is home to many African primates, including chimpanzees.

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 statements describe the Kibale National Forest 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. It has soil that is poor in nutrients. The following statement does not describe Kibale National Forest: 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.


Question: Which of these states is farthest east?

Choices:
- New Mexico
- Florida
- Arkansas
- Kansas

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. Florida is farthest east.


Question: Which continent is highlighted?

Choices:
- Asia
- Africa
- Europe
- Australia

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 Asia.


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 south pole of one magnet is closest to the north pole of the other magnet. Opposite poles attract. So, these magnets will attract each other.


Question: What is the capital of Mississippi?

Choices:
- Jackson
- Frankfort
- Charleston
- Biloxi

social science

Identify state capitals of the Southeast

Solution: Jackson is the capital of Mississippi.


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 stronger in Pair 2.
- The magnetic force is stronger in Pair 1.

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

natural science

Magnets can pull or push on each other without touching. When magnets attract, they pull together. When magnets repel, they push apart.
These pulls and pushes between magnets are called magnetic forces. The stronger the magnetic force between two magnets, the more strongly the magnets attract or repel each other.

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: Select the bird below.

Choices:
- rabbit
- albatross
- western gorilla
- Galapagos giant tortoise

Birds have feathers, two wings, and a beak.
Birds are warm-blooded. Warm-blooded animals can control their body temperature.
A griffon vulture is an example of a bird.

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 rabbit is a mammal. It has fur and feeds its young milk.
Rabbits live underground in burrows. A group of rabbit burrows is called a warren.
An albatross is a bird. It has feathers, two wings, and a beak.
Albatrosses live near the ocean. They hunt squid, fish, and other small animals.
A Galapagos giant tortoise is a reptile. It has scaly, waterproof skin.
Galapagos tortoises live on the Galapagos Islands in the Pacific Ocean. They can live to be over 150 years old!
A western gorilla is a mammal. It has fur and feeds its young milk.
Gorillas live in groups called troops. The largest male in the troop is usually the leader.


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.


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

Choices:
- blue
- fuzzy
- slippery

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 slippery object is hard to hold onto or stand on. None of the objects are slippery.
A fuzzy object is covered in soft hair. All three objects are fuzzy.
Blue is a color.
This color is blue. The yarn pom pom is blue, but the tennis ball and the boots are not.
The property that all three objects have in common is fuzzy.


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


Question: What is the capital of Wisconsin?

Choices:
- Madison
- Lincoln
- Dover
- Green Bay

social science

Solution: Madison is the capital of Wisconsin.


Question: What is the capital of Maine?

Choices:
- Baton Rouge
- Portland
- Augusta
- Manchester

social science

Identify state capitals of the Northeast

Solution: Augusta is the capital of Maine.


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

Choices:
- whether she added enough nutrients to help the bacteria produce 20% more insulin
- whether producing more insulin would help the bacteria grow faster
- whether different types of bacteria would need different nutrients to produce insulin

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.

People with diabetes sometimes take a medicine made from insulin. Insulin can be made by a special type of bacteria. Kathleen was a bioengineer who wanted to increase the amount of insulin that the bacteria produced by 20%. She read that giving the bacteria more nutrients could affect the amount of insulin they produced. So, Kathleen gave extra nutrients to some of the bacteria. Then, she measured how much insulin those bacteria produced compared to bacteria that did not get extra nutrients.
Figure: studying bacteria in a laboratory.

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 country is highlighted?

Choices:
- Haiti
- Saint Kitts and Nevis
- the Dominican Republic
- Dominica

social science

Identify and select countries of the Caribbean

Solution: This country is Dominica.


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

Choices:
- salty
- fuzzy
- smooth

natural science

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

Solution:
Look at each object.
For each object, decide if it has that property.
Potato chips have a salty taste. All four objects are salty.
A fuzzy object is covered in soft hair. The cracker is not fuzzy.
A smooth object is not scratchy or rough. The potato chips, the fries, and the cracker are not smooth.
The property that all four objects have in common is salty.


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

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

natural science

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

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


Question: What can Duncan and Sam trade to each get what they want?

Choices:
- Duncan can trade his tomatoes for Sam's broccoli.
- Duncan can trade his tomatoes for Sam's carrots.
- Sam can trade his almonds for Duncan's tomatoes.
- Sam can trade his broccoli for Duncan's oranges.

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.
Duncan and Sam open their lunch boxes in the school cafeteria. Neither Duncan nor Sam got everything that they wanted. The table below shows which items they each wanted:

Look at the images of their lunches. Then answer the question below.
Duncan's lunch Sam's lunch

social science

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


Question: Which animal's skin is better adapted as a warning sign to ward off predators?

Choices:
- opalescent nudibranch
- lechwe

Fire salamanders have poisonous glands in their brightly colored skin. The bright colors serve as a warning sign that the animal is poisonous. The 's skin is adapted to ward off predators.
Figure: fire salamander.

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 fire salamander.
The fire salamander has a poisonous body with brightly colored skin. Its skin is adapted to ward off predators. The bright colors serve as a warning sign that the fire salamander is poisonous.
Now look at each animal. Figure out which animal has a similar adaptation.
The opalescent nudibranch has stinging cells in its brightly colored skin. Its skin is adapted to ward off predators.
The lechwe has light-brown fur covering its skin. Its skin is not adapted to be a warning sign that wards off predators.


Question:
Complete the statement.
Hydrogen fluoride is ().

Choices:
- an elementary substance
- a compound

The model below represents a molecule of hydrogen fluoride. Hydrogen fluoride is used to make chemicals that can help keep refrigerators cool.

natural science

Classify elementary substances and compounds using models

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

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


Question: Select the organism in the same genus as the common kestrel.

Choices:
- Falco sparverius
- Tigrisoma mexicanum
- Ardea herodias

This organism is a common kestrel. Its scientific name is Falco tinnunculus.

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 common kestrel's scientific name is Falco tinnunculus. The first word of its scientific name is Falco.
Ardea herodias is in the genus Ardea. The first word of its scientific name is Ardea. So, Ardea herodias and Falco tinnunculus are not in the same genus.
Falco sparverius is in the genus Falco. The first word of its scientific name is Falco. So, Falco sparverius and Falco tinnunculus are in the same genus.
Tigrisoma mexicanum is in the genus Tigrisoma. The first word of its scientific name is Tigrisoma. So, Tigrisoma mexicanum and Falco tinnunculus are not in the same genus.


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

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

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

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

natural science

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


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

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

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

natural science

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

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


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

Choices:
- rough-legged hawk
- parasitic jaeger
- Arctic fox
- snowy owl
- barren-ground caribou

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 lichen.
The only arrow pointing to the rough-legged hawk starts from the parasitic jaeger. The only arrow pointing to the parasitic jaeger starts from the brown lemming. The brown lemming has two arrows pointing to it. These arrows start from the bear sedge and the bilberry. Neither the bear sedge nor the bilberry has any arrows pointing to it. So, in this food web, matter does not move from the lichen to the rough-legged hawk.
The only arrow pointing to the snowy owl starts from the short-tailed weasel. The only arrow pointing to the short-tailed weasel starts from the brown lemming. The brown lemming has two arrows pointing to it. These arrows start from the bear sedge and the bilberry. Neither the bear sedge nor the bilberry has any arrows pointing to it. So, in this food web, matter does not move from the lichen to the snowy owl.
The only arrow pointing to the parasitic jaeger starts from the brown lemming. The brown lemming has two arrows pointing to it. These arrows start from the bear sedge and the bilberry. Neither the bear sedge nor the bilberry has any arrows pointing to it. So, in this food web, matter does not move from the lichen to the parasitic jaeger.There is one path matter can take from the lichen to the barren-ground caribou: lichen->barren-ground caribou. Arctic fox. The Arctic fox has two arrows pointing to it. One arrow starts from the bilberry. The bilberry does not have any arrows pointing to it. The other arrow pointing to the Arctic fox starts from the brown lemming. The brown lemming has two arrows pointing to it. These arrows start from the bear sedge and the bilberry. Neither the bear sedge nor the bilberry has any arrows pointing to it. So, in this food web, matter does not move from the lichen to the Arctic fox..


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

Choices:
- transparent
- fragile
- 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.

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. All three objects are flexible.
A fragile object will break into pieces if you drop it. None of the objects are fragile.
You can see clearly through a transparent object. None of the objects are transparent.
The property that all three objects have in common is flexible.


Question: Which continent is highlighted?

Choices:
- Antarctica
- South America
- Asia
- Europe

social science

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

Solution: This continent is South America.


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

Choices:
- South America
- Antarctica
- Australia

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 Australia or South America.


Question:
Complete the text to describe the diagram.
Solute particles moved in both directions across the permeable membrane. But more solute particles moved across the membrane (). When there was an equal concentration on both sides, the particles reached equilibrium.

Choices:
- to the left than to the right
- to the right than to the left

The diagram below shows a solution with one solute. Each solute particle is represented by a yellow ball. The solution fills a closed container that is divided in half by a membrane. The membrane, represented by a dotted line, is permeable to the solute particles.
The diagram shows how the solution can change over time during the process of diffusion.

natural science

In a solution, solute particles move and spread throughout the solvent. The diagram below shows how a solution can change over time. Solute particles move from the area where they are at a higher concentration to the area where they are at a lower concentration. This movement happens through the process of diffusion.
As a result of diffusion, the concentration of solute particles becomes equal throughout the solution. When this happens, the solute particles reach equilibrium. At equilibrium, the solute particles do not stop moving. But their concentration throughout the solution stays the same.
Membranes, or thin boundaries, can divide solutions into parts. A membrane is permeable to a solute when particles of the solute can pass through gaps in the membrane. In this case, solute particles can move freely across the membrane from one side to the other.
So, for the solute particles to reach equilibrium, more particles will move across a permeable membrane from the side with a higher concentration of solute particles to the side with a lower concentration. At equilibrium, the concentration on both sides of the membrane is equal.

Solution:
Look at the diagram again. It shows you how the solution changed during the process of diffusion.
Before the solute particles reached equilibrium, there were 2 solute particles on the left side of the membrane and 6 solute particles on the right side of the membrane.
When the solute particles reached equilibrium, there were 4 solute particles on each side of the membrane. There were 2 more solute particles on the left side of the membrane than before.
So, for the solute particles to reach equilibrium, more solute particles must have moved across the membrane to the left than to the right.


Question: Select the organism in the same genus as the red kangaroo.

Choices:
- Cervus canadensis
- Camelus bactrianus
- Macropus giganteus

This organism is a red kangaroo. Its scientific name is Macropus rufus.

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 red kangaroo's scientific name is Macropus rufus. The first word of its scientific name is Macropus.
Cervus canadensis is in the genus Cervus. The first word of its scientific name is Cervus. So, Cervus canadensis and Macropus rufus are not in the same genus.
Macropus giganteus is in the genus Macropus. The first word of its scientific name is Macropus. So, Macropus giganteus and Macropus rufus are in the same genus.
Camelus bactrianus is in the genus Camelus. The first word of its scientific name is Camelus. So, Camelus bactrianus and Macropus rufus are not in the same genus.


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

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

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.

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

natural science

Evaluate tests of engineering-design solutions

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


Question: Which continent is highlighted?

Choices:
- Europe
- South America
- Antarctica
- Africa

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 Antarctica.


Question: Which animal's skin is better adapted as a warning sign to ward off predators?

Choices:
- sharpnose-puffer
- gray tree frog

Blue poison dart frogs have poisonous glands in their brightly colored skin. The bright colors serve as a warning sign that the animal is poisonous. The 's skin is adapted to ward off predators.
Figure: blue poison dart frog.

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 blue poison dart frog.
The blue poison dart frog has poisonous glands in its brightly colored skin. Its skin is adapted to ward off predators. The bright colors serve as a warning sign that the blue poison dart frog is poisonous.
Now look at each animal. Figure out which animal has a similar adaptation.
The sharpnose-puffer has a poisonous body with brightly colored skin. Its skin is adapted to ward off predators.
The gray tree frog has gray-brown skin. Its skin is not adapted to be a warning sign that wards off predators.


Question: What is the name of the colony shown?

Choices:
- Rhode Island
- Michigan
- Massachusetts
- New Jersey

social science

Solution: The colony is New Jersey.


Question: Which ocean is highlighted?

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

social science

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

Solution: This is the Atlantic Ocean.


Question: Which country is highlighted?

Choices:
- the Federated States of Micronesia
- New Zealand
- the Marshall Islands
- Palau

social science

Identify and select countries of Oceania

Solution: This country is the Federated States of Micronesia.


Question:
Complete the sentence.
Pollination is what happens when ().

Choices:
- pollen lands on a female cone
- sperm fuses with an egg

Male cones make pollen. Wind can blow pollen from a male cone to a female 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:
When pollen lands on a female cone, it is called pollination. This photograph shows wind blowing pollen from the male cones on a Japanese cedar tree.
After a female cone is pollinated, its eggs can be fertilized. Fertilization is what happens when male cells from the pollen combine with eggs.


Question: Select the organism in the same genus as the European nightjar.

Choices:
- Caprimulgus macrurus
- Ulex europaeus
- Acanthaster planci

This organism is a European nightjar. Its scientific name is Caprimulgus europaeus.

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 European nightjar's scientific name is Caprimulgus europaeus. The first word of its scientific name is Caprimulgus.
Ulex europaeus and Caprimulgus europaeus are not in the same genus.
These organisms are not in the same genus, but part of their scientific names is the same. Ulex europaeus and Caprimulgus europaeus have the same species name within their genus, europaeus. But the first words of their scientific names are different. Ulex europaeus is in the genus Ulex, and Caprimulgus europaeus is in the genus Caprimulgus.
Acanthaster planci is in the genus Acanthaster. The first word of its scientific name is Acanthaster. So, Acanthaster planci and Caprimulgus europaeus are not in the same genus.
Caprimulgus macrurus is in the genus Caprimulgus. The first word of its scientific name is Caprimulgus. So, Caprimulgus macrurus and Caprimulgus europaeus are in the same genus.


Question: What is the capital of California?

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

social science

Solution: Sacramento is the capital of California.


Question: Which of the following statements is true?

Choices:
- A flavorant might be both found in nature and made in a chemical factory.
- A substance's chemical structure depends only on the number and types of atoms in each molecule of the substance.

A substance's physical and chemical properties are all determined by its chemical structure. Its chemical structure depends on the number and types of atoms in each of its molecules, as well as on how those atoms are arranged.
One property of a substance is its flavor, which is its odor and taste combined. The chemical structure of a substance determines both the kind of flavor it has and the strength of that flavor.
Syrups containing flavorants are used to add flavor to snow cones.
Substances that have especially interesting and strong flavors are often added to food to change or enhance the food's flavor. These substances are called flavorants. Flavorants can be found in nature, made in a chemical factory, or both.
One example of a flavorant is methyl anthranilate. This flavorant is often used to add a grape flavor to syrups, candy, and other sweets. Methyl anthranilate is found naturally in certain types of grapes, but it can also be made by workers in a chemical factory.

natural science

Explore chemical structure and properties: food flavors


Question: What is the name of the colony shown?

Choices:
- Maryland
- Washington, D.C.
- Virginia
- New York

social science

Solution: The colony is Maryland.


Question:
Is the following statement about our solar system true or false?
There are twice as many ice planets as rocky planets.

Choices:
- false
- true

Use the data to answer the question below.

natural science

Analyze data to compare properties of planets

A planet's volume tells you the size of the planet.
The primary composition of a planet is what the planet is made mainly of. In our solar system, planets are made mainly of rock, gas, or ice.

Solution: The table tells you that there are two ice planets and four rocky planets. So, there are half as many ice planets as rocky planets.


Question: What is the name of the colony shown?

Choices:
- New Hampshire
- Georgia
- Rhode Island
- Connecticut

social science

Solution: The colony is Rhode Island.


Question: Which ocean is highlighted?

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

social science

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

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


Question: Which animal's skin is better adapted as a warning sign to ward off predators?

Choices:
- lichen katydid
- flamboyant cuttlefish

Lionfish can release venom from the spines on their brightly colored bodies. The bright colors serve as a warning sign that the animal is venomous. The 's skin is adapted to ward off predators.
Figure: lionfish.

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 lionfish.
The lionfish has venomous spines and brightly colored skin. Its skin is adapted to ward off predators. The bright colors serve as a warning sign that the lionfish is venomous.
Now look at each animal. Figure out which animal has a similar adaptation.
The flamboyant cuttlefish has a poisonous body with brightly colored skin. Its skin is adapted to ward off predators.
The lichen katydid has green and white patches on its body. Its skin is not adapted to be a warning sign that wards off predators.


Question: Which better describes the Jardines de la Reina National Park ecosystem?

Choices:
- It has bright sunlight. It also has shallow water.
- It has water with not much salt. It also has only a few types of organisms.

Figure: Jardines de la Reina National Park.
Jardines de la Reina National Park is a tropical coral reef ecosystem near the southern coast of Cuba.

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 tropical coral reef is a type of ecosystem. Tropical coral reefs have the following features: shallow, salty water, bright sunlight, and many different types of organisms. So, Jardines de la Reina National Park has bright sunlight. It also has shallow water.


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

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

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

natural science

Identify how particle motion affects temperature and pressure

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

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


Question: What is the expected ratio of offspring that have horns to offspring that do not have horns? Choose the most likely ratio.

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

In a group of cows, some individuals have horns and others do not. In this group, the gene for the horns trait has two alleles. The allele for having horns (h) is recessive to the allele for not having horns (H).
This Punnett square shows a cross between two cows.

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 that do or do not have horns, consider whether each phenotype is the dominant or recessive allele's version of the horns trait. The question tells you that the h allele, which is for having horns, is recessive to the H allele, which is for not having horns.
Having horns is the recessive allele's version of the horns trait. A cow with the recessive version of the horns trait must have only recessive alleles for the horns gene. So, offspring that have horns must have the genotype hh.
There are 0 boxes in the Punnett square with the genotype hh.
Not having horns is the dominant allele's version of the horns trait. A cow with the dominant version of the horns trait must have at least one dominant allele for the horns gene. So, offspring that do not have horns must have the genotype HH or Hh.
All 4 boxes in the Punnett square have the genotype HH or Hh.
So, the expected ratio of offspring that have horns to offspring that do not have horns is 0:4. This means that, based on the Punnett square, this cross will never produce offspring that have horns. Instead, this cross is expected to always produce offspring that do not have horns.


Question:
Is the following statement about our solar system true or false?
The volume of Uranus is less than ten times the volume of Neptune.

Choices:
- false
- true

Use the data to answer the question below.

natural science

Analyze data to compare properties of planets

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

Solution:
To determine if this statement is true, calculate the value of ten times the volume of Neptune.
Then compare the result to the volume of Uranus. The volume of Uranus is 6.83 x 10^13 km^3, which is less than 6.25 x 10^14 km^3. So, the volume of Uranus is less than ten times the volume of Neptune.


Question:
Complete the statement.
Iodine is ().

Choices:
- an elementary substance
- a compound

The model below represents a molecule of iodine. Iodine is found in some types of disinfectants.

natural science

Classify elementary substances and compounds using models

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

Solution:
Count the number of chemical elements represented in the model. Then, decide if iodine is an elementary substance or a compound.
In this model, both balls are labeled with I. So, the model shows you that iodine is made of one chemical element.
Substances made of only one chemical element are elementary substances. So, iodine is an elementary substance.


Question: What is the capital of South Dakota?

Choices:
- Pierre
- Rapid City
- Indianapolis
- Sacramento

social science

Solution: Pierre is the capital of South Dakota.


Question: Based on the arrows, which of the following living things is an omnivore?

Choices:
- phytoplankton
- plainfin midshipman

Below is a food web from an ocean ecosystem. The ecosystem is in Monterey Bay, off the coast of California.
A food web is a model that shows how the matter eaten by living things moves through an ecosystem. The arrows show how matter moves through the food web.

natural science

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

Solution:
Omnivores are consumers that eat both producers and other consumers. So, an omnivore has arrows pointing to it from at least one producer and at least one consumer.
The phytoplankton does not have any arrows pointing to it. So, the phytoplankton is a producer, not an omnivore.
The plainfin midshipman has an arrow pointing to it from the phytoplankton, which is a producer. The plainfin midshipman also has an arrow pointing to it from the zooplankton, which is a consumer. The plainfin midshipman eats a producer and a consumer, so it is an omnivore.


Question:
Is the following statement about our solar system true or false?
The volume of Mars is more than three times as large as Mercury's.

Choices:
- false
- true

Use the data to answer the question below.

natural science

Analyze data to compare properties of planets

A planet's volume tells you the size of the planet.
The primary composition of a planet is what the planet is made mainly of. In our solar system, planets are made mainly of rock, gas, or ice.

Solution:
To determine if this statement is true, calculate the value of three times the volume of Mercury.
Then compare the result to the volume of Mars. The volume of Mars is 160 billion km^3, which is less than 180 billion km^3. So, the volume of Mars is less than three times as large as Mercury's.


Question: What is the capital of Nebraska?

Choices:
- Lincoln
- Omaha
- Savannah
- Indianapolis

social science

Solution: Lincoln is the capital of Nebraska.


Question: What is the capital of Pennsylvania?

Choices:
- Pittsburgh
- Philadelphia
- Phoenix
- Harrisburg

social science

Identify state capitals of the Northeast

Solution: Harrisburg is the capital of Pennsylvania.


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

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

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

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

natural science

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


Question: 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 the same in both pairs.
- The magnitude of the magnetic force is greater in Pair 1.
- The magnitude of the magnetic force is greater 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 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: What is the capital of Alaska?

Choices:
- Fairbanks
- Juneau
- Tucson
- Cheyenne

social science

Solution: Juneau is the capital of Alaska.


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

Choices:
- soft
- flexible
- slippery

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 slippery object is hard to hold onto or stand on. All three objects are slippery.
A flexible object can be folded or bent without breaking easily. The wet ice cube is not flexible.
A soft object changes shape when pressed or squeezed. The butter is soft, but the wet ice cube is not.
The property that all three objects have in common is slippery.


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 south pole of one magnet is closest to the south pole of the other magnet. Poles that are the same repel. So, these magnets will repel each other.


Question: Which property matches this object?

Choices:
- bendable
- bouncy

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells.

Solution:
Look at the object.
Think about each property.
A bouncy object will bounce back from the floor if you drop it. The tin foil is not bouncy.
A bendable object can be bent without breaking. The tin foil is bendable.


Question:
Is the following statement about our solar system true or false?
Half of the planets are made mainly of gas or ice.

Choices:
- true
- false

Use the data to answer the question below.

natural science

Analyze data to compare properties of planets

A planet's volume tells you the size of the planet.
The primary composition of a planet is what the planet is made mainly of. In our solar system, planets are made mainly of rock, gas, or ice.

Solution: The table tells you that of the eight planets, two are made mainly of gas and two are made mainly of ice. So, four of the eight, or half, of the planets are made mainly of gas or ice.


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 the same in both pairs.
- The magnitude of the magnetic force is smaller in Pair 1.
- The magnitude of the magnetic force is smaller 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, 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 2 than in Pair 1. So, the magnitude of the magnetic force is smaller in Pair 2 than in Pair 1.


Question: Which material is these jeans made of?

Choices:
- metal
- rock

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 jeans.
The jeans are made of two different materials. The buttons and zipper of the jeans are made of metal. The rest of the jeans are made of cotton.
Jeans are made of a type of cotton fabric called denim. Denim is a fabric woven in a special way.


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

Choices:
- June, July, and August
- April and May
- January and February

Use the graph to answer the question below.

natural science

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

Solution:
To describe the average temperature trends in Adelaide, look at the graph.
Choice "Feb" is incorrect.
Choice "Apr" is incorrect.
Choice "May" is incorrect.
Choice "Jun" is incorrect.
Choice "Jul" is incorrect.
Choice "Aug" is incorrect.
Choice "Jan" is incorrect.
The average temperatures in January and February are just above 20°C. These months have the highest average temperatures of all of the months. So, they are hotter than the other months.


Question: What can Kevin and Lily trade to each get what they want?

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

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

social science

Solution:
Kevin wanted broccoli in his lunch and Lily was hoping for tomatoes. Look at the labeled part of the images.
Kevin has tomatoes. Lily 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: During this time, thermal energy was transferred from () to ().

Choices:
- each battery . . . the surroundings
- the surroundings . . . each battery

Two friends bought phones that cost different amounts but had identical batteries. After using the phones for a while, both friends had to turn them off to let the batteries cool. This table shows how the temperature of each battery changed over 5minutes.

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 battery decreased, which means that the thermal energy of each battery decreased. So, thermal energy was transferred from each battery to the surroundings.


Question: Which of the following is on the map?

Choices:
- water in clouds
- water in rivers and lakes

Read the passage. Then answer the question.
This is a map of Earth. The map uses color to show parts of Earth that are covered by land and water. The map uses white to show large sheets of ice and snow called glaciers.
The map's legend, or information box, shows the feature that each color represents.

natural science

Solution:
The map uses blue to show liquid water in rivers, lakes, and oceans. It uses white to show water that is frozen in glaciers.
The map shows only water that is on the surface of Earth. It does not show water that is underground or in clouds. Other maps might use different colors to show water that is underground or in clouds.


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

Choices:
- false
- true

Use the data to answer the question below.

natural science

Analyze data to compare properties of planets

A planet's volume tells you the size of the planet.
The primary composition of a planet is what the planet is made mainly of. In our solar system, planets are made mainly of rock, gas, or ice.

Solution: The table tells you that the four largest planets are Jupiter, Saturn, Uranus, and Neptune. Jupiter and Saturn are made mainly of gas. Uranus and Neptune are made mainly of ice. So, of the four largest planets, two are made mainly of gas.


Question: What is the expected ratio of offspring with a reddish-brown coat to offspring with a black coat? Choose the most likely ratio.

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

In a group of horses, some individuals have a black coat and others have a reddish-brown coat. In this group, the gene for the coat color trait has two alleles. The allele for a black coat (L) is dominant over the allele for a reddish-brown coat (l).
This Punnett square shows a cross between two horses.

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 reddish-brown coat or a black coat, consider whether each phenotype is the dominant or recessive allele's version of the coat color trait. The question tells you that the L allele, which is for a black coat, is dominant over the l allele, which is for a reddish-brown coat.
A reddish-brown coat is the recessive allele's version of the coat color trait. A horse with the recessive version of the coat color trait must have only recessive alleles for the coat color gene. So, offspring with a reddish-brown coat must have the genotype ll.
There are 2 boxes in the Punnett square with the genotype ll. These boxes are highlighted below.
A black coat is the dominant allele's version of the coat color trait. A horse with the dominant version of the coat color trait must have at least one dominant allele for the coat color gene. So, offspring with a black coat must have the genotype LL or Ll.
There are 2 boxes in the Punnett square with the genotype LL or Ll. These boxes are highlighted below.
So, the expected ratio of offspring with a reddish-brown coat to offspring with a black coat is 2:2. This means that, on average, this cross will produce 2 offspring with a reddish-brown coat for every 2 offspring with a black coat.


Question: Which animal is also adapted for flight?

Choices:
- flying fox
- European mole

s fly high above the ground in search of food. The vulture has wings instead of arms. It is adapted for flight.
Figure: Cape vulture.

natural science

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

Solution:
Look at the picture of the Cape vulture.
The Cape vulture has large, powerful wings. It is adapted for flight. Long, powerful wings help the Cape vulture travel long distances by air.
Now look at each animal. Figure out which animal has a similar adaptation.
The flying fox has large, powerful wings. It is adapted for flight.
The European mole has short legs. It is not adapted for flight. The European mole uses its legs for crawling.


Question: Which ocean is highlighted?

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

social science

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

Solution: This is the Arctic Ocean.


Question: Which of the following could Pamela and Kimi's test show?

Choices:
- if the concrete from each batch took the same amount of time to dry
- if a new batch of concrete was firm enough to use

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.

Pamela and Kimi were making batches of concrete for a construction project. To make the concrete, they mixed together dry cement powder, gravel, and water. Then, they checked if each batch was firm enough using a test called a slump test.
They poured some of the fresh concrete into an upside-down metal cone. They left the concrete in the metal cone for 30 seconds. Then, they lifted the cone to see if the concrete stayed in a cone shape or if it collapsed. If the concrete in a batch collapsed, they would know the batch should not be used.
Figure: preparing a concrete slump test.

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: Can Leopardus wiedii cells make their own food?

Choices:
- no
- yes

This organism is Leopardus wiedii. It is a member of the animal kingdom.
Leopardus wiedii is commonly called a margay. Margays live in the forest in Central and South America. Margays are nocturnal. A nocturnal animal sleeps most of the day and is awake at night.

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: Leopardus wiedii is an animal. Animal cells cannot make their own food. Animals get their food by digesting other organisms.


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

Choices:
- the surroundings . . . each salmon
- each salmon . . . the surroundings

Colin lit the charcoal in his grill to cook two identical salmon. He put one fish on the left half of the grill and one fish on the right half of the grill. This table shows how the temperature of each salmon changed over 6minutes.

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