Question: Select the fish below.

Choices:
- piranha
- American bullfrog
- olive toad
- sea otter

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

natural science

Identify mammals, birds, fish, reptiles, and amphibians

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

Solution:
An American bullfrog is an amphibian. It has moist skin and begins its life in water.
Frogs live near water or in damp places. Most frogs lay their eggs in water.
A sea otter is a mammal. It has fur and feeds its young milk.
Sea otters have very thick fur. Their fur keeps them warm in cold water.
An olive toad is an amphibian. It has moist skin and begins its life in water.
Toads do not have teeth! They swallow their food whole.
A piranha is a fish. It lives underwater. It has fins, not limbs.
Piranhas have sharp teeth. Piranhas hunt in groups. A group of piranhas can eat a large animal.


Question: Which bird's beak is also adapted to get nectar out of long flowers?

Choices:
- green violetear
- secretary bird

s live in the woodlands and meadows of California and Mexico. The shape of this hummingbird's beak is adapted to get nectar out of long flowers.
Figure: Allen's hummingbird.

natural science

Animal adaptations: beaks, mouths, and necks

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

Solution:
Look at the picture of the Allen's hummingbird.
The Allen's hummingbird has a long, thin beak. Its beak is adapted to get nectar out of long flowers. The Allen's hummingbird's long, thin beak can reach deep into the flowers.
Now look at each bird. Figure out which bird has a similar adaptation.
The green violetear has a long, thin beak. Its beak is adapted to get nectar out of long flowers.
The secretary bird has a sharp hooked beak. Its beak is not adapted to get nectar out of long flowers. The secretary bird uses its beak to eat meat.


Question:
Complete the sentence.
The Cascade Range formed at a () boundary.

Choices:
- divergent
- transform
- convergent

Read the passage and look at the picture.
The Cascade Range is a volcanic arc in the Pacific Northwest that begins in California and runs north into British Columbia. As the North American Plate and the Juan de Fuca Plate move toward each other, oceanic crust of the Juan de Fuca Plate subducts, or sinks, below continental crust of the North American Plate.
There are eighteen volcanoes in the Cascade Range, and some of them are still active. Mount St. Helens is an active volcano near Seattle, Washington. It last erupted in May of 1980.

natural science

Describe tectonic plate boundaries around the world

The outer layer of Earth is broken up into many pieces called tectonic plates, or simply plates. The breaks between plates are called plate boundaries. Plate boundaries are classified by the way the plates are moving relative to each other:
At a divergent boundary, two plates are moving away from each other.
At a transform boundary, two plates are sliding past each other.
At a convergent boundary, two plates are moving toward each other.
ocean-continent subduction zone
One type of convergent boundary is an ocean-continent subduction zone, which forms when a plate with oceanic crust and a plate with continental crust move toward each other. The oceanic crust subducts, or sinks, below the continental crust.
As the oceanic crust subducts, a deep-sea trench forms at the plate boundary. Some rock in the subducting plate melts into magma and rises toward the surface. The magma cools and hardens to create a string of volcanoes called a volcanic arc.

Solution:
To figure out what type of plate boundary formed the Cascade Range, you need to know how the tectonic plates interacted. To find this out, read the passage carefully.
The Cascade Range is a volcanic arc in the Pacific Northwest that begins in California and runs north into British Columbia. As the North American Plate and the Juan de Fuca Plate move toward each other, oceanic crust of the Juan de Fuca Plate subducts, or sinks, below continental crust of the North American Plate.
There are eighteen volcanoes in the Cascade Range, and some of them are still active. Mount St. Helens is an active volcano near Seattle, Washington. It last erupted in May of 1980.
The underlined part of the passage explains that the Cascade Range formed as the two plates moved toward each other. So, the Cascade Range formed at a convergent boundary.


Question: Which animal is also adapted for climbing trees?

Choices:
- lama
- bare-eared squirrel monkey

Vervet monkeys live in the grasslands and forests of Africa. They climb trees to find food and shelter. The 's hands and feet are adapted for climbing trees.
Figure: vervet monkey.

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 vervet monkey.
The vervet monkey has long fingers and toes. It is adapted for climbing trees. The vervet monkey uses its long fingers and toes to hold on to branches while climbing.
Now look at each animal. Figure out which animal has a similar adaptation.
The bare-eared squirrel monkey has long fingers and toes. It is adapted for climbing trees.
The lama has four hoofed feet. It is not adapted for climbing trees. The lama uses its feet to walk and run.


Question: What is the capital of Idaho?

Choices:
- Austin
- Boise
- Santa Fe
- Des Moines

social science

Solution: Boise is the capital of Idaho.


Question: What is the capital of West Virginia?

Choices:
- Huntington
- Oklahoma City
- Charleston
- Buffalo

social science

Identify state capitals of the Southeast

Solution: Charleston is the capital of West Virginia.


Question: Select the amphibian below.

Choices:
- red-spotted newt
- human

Amphibians have moist skin and begin their lives in water. A common toad is an example of an amphibian.

natural science

Identify mammals, birds, fish, reptiles, and amphibians

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

Solution:
A red-spotted newt is an amphibian. It has moist skin and begins its life in water.
A human is a mammal. It has hair and feeds its young milk.


Question: Which country is highlighted?

Choices:
- Grenada
- Trinidad and Tobago
- Saint Lucia
- Saint Vincent and the Grenadines

social science

Identify and select countries of the Caribbean

Solution: This country is Grenada.


Question: What is the capital of Montana?

Choices:
- Anchorage
- Los Angeles
- Helena
- Honolulu

social science

Solution: Helena is the capital of Montana.


Question: What can Arianna and Sidney trade to each get what they want?

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

social science

Solution:
Arianna wanted broccoli in her lunch and Sidney was hoping for tomatoes. Look at the labeled part of the images.
Arianna has tomatoes. Sidney 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: Which better describes the Amazon rain forest ecosystem?

Choices:
- It has cold winters. It also has many different types of organisms.
- It has year-round rain. It also has many different types of organisms.

Figure: Amazon rain forest.
The Amazon rain forest is a tropical rain forest ecosystem located in Brazil, Peru, and several other South American countries.

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 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 Amazon rain forest has year-round rain. It also has many different types of organisms.


Question: What can Dustin and Irma trade to each get what they want?

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

social science

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


Question: What location was involved in the triangular trade?

Choices:
- China
- the Thirteen Colonies

By the 1700s, merchants in the Thirteen Colonies traded goods across the Atlantic Ocean in a pattern called triangular trade. Look at the map showing this trade. Then answer the question below.

social science

Causes of the American Revolution: introduction to mercantilism and the Navigation Acts

Solution:
Look at the map.
The arrows on the map show that goods moved to and from these locations:
China was not involved in the triangular trade.


Question: Select the organism in the same species as the Canada lynx.

Choices:
- Lynx rufus
- Macropus agilis
- Lynx canadensis

This organism is a Canada lynx. Its scientific name is Lynx canadensis.

natural science

Use scientific names to classify organisms

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

Solution:
A Canada lynx's scientific name is Lynx canadensis.
Macropus agilis does not have the same scientific name as a Canada lynx. So, Lynx canadensis and Macropus agilis are not in the same species.
Lynx canadensis is in the same genus as Lynx rufus, but they are not in the same species.
Organisms in the same species have the same scientific names. Lynx canadensis and Lynx rufus are different species within the same genus.
Lynx canadensis has the same scientific name as a Canada lynx. So, these organisms are in the same species.


Question: What is the name of the colony shown?

Choices:
- Massachusetts
- Pennsylvania
- South Carolina
- Wisconsin

social science

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


Question: What can Elise and Nolan trade to each get what they want?

Choices:
- Nolan can trade his broccoli for Elise's oranges.
- Elise can trade her tomatoes for Nolan's broccoli.
- Elise can trade her tomatoes for Nolan's carrots.
- Nolan can trade his almonds for Elise'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.
Elise and Nolan open their lunch boxes in the school cafeteria. Neither Elise nor Nolan 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.
Elise's lunch Nolan's lunch

social science

Solution:
Look at the table and images.
Elise wants broccoli. Nolan 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: Will these magnets attract or repel each other?

Choices:
- repel
- attract

natural science

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

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


Question: What can Nina and Ivan trade to each get what they want?

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

social science

Solution:
Nina wanted broccoli in her lunch and Ivan was hoping for tomatoes. Look at the labeled part of the images.
Nina has tomatoes. Ivan 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: Which property matches this object?

Choices:
- colorful
- sticky

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 colorful object has one or more bright colors. The flip-flops are colorful.
A sticky object can stick to other things. The flip-flops are not sticky.


Question: What is the capital of Washington?

Choices:
- Sacramento
- Boise
- Olympia
- Seattle

social science

Solution: Olympia is the capital of Washington.


Question: What is the name of the colony shown?

Choices:
- Florida
- South Carolina
- Maryland
- Tennessee

social science

Solution: The colony is Maryland.


Question: Which better describes the tide pool ecosystems in Tongue Point Marine Life Sanctuary?

Choices:
- It has daily flooding and draining of seawater. It also has many different types of organisms.
- It has daily flooding and draining of seawater. It also has water that is poor in nutrients.

Figure: Tongue Point Marine Life Sanctuary.
Tongue Point Marine Life Sanctuary is in western Washington State. The park is on the coast of the Pacific Ocean. It has many tide pool ecosystems.

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 tide pool is a type of ecosystem. Tide pool ecosystems have the following features: daily flooding and draining of seawater, water that is rich in nutrients, and many different types of organisms. So, the tide pool ecosystems in Tongue Point Marine Life Sanctuary have daily flooding and draining of seawater. They also have many different types of organisms.


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

Choices:
- Does apple juice expand more or less than water when it freezes?
- Does water freeze more quickly than apple juice?

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

Edwin poured 30 milliliters of water into each of six measuring cups. He poured the same volume of apple juice into another six measuring cups. He kept the measuring cups in a freezer for 48 hours. Edwin then observed the frozen liquids' volumes in the measuring cups. He measured the amount the volumes increased to see how much the liquids had expanded while freezing. He compared how much the water expanded to how much the apple juice expanded.
Figure: water in a measuring cup.

natural science

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


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

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.
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 Mercury.
Then compare the result to the volume of Earth. The volume of Earth is 1.08 x 10^12 km^3, which is greater than 6.08 x 10^11 km^3. So, the volume of Earth is more than ten times the volume of Mercury.


Question: Which continent is highlighted?

Choices:
- Europe
- Africa
- Asia
- North America

social science

A continent is one of the seven largest areas of land on earth.

Solution: This continent is Asia.


Question: Which ocean is highlighted?

Choices:
- the Southern Ocean
- the Indian 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 Southern Ocean.
The Southern Ocean reaches from the shores of Antarctica to 60° South latitude.


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

Choices:
- the surroundings . . . each bottle
- each bottle . . . the surroundings

Two bottles of soda were sitting on a porch on a hot day. The two bottles were identical, except that one bottle was made of brown glass and one bottle was made of clear glass. This table shows how the temperature of each bottle changed over 25minutes.

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


Question: Select the bird below.

Choices:
- painted stork
- human

Birds have feathers, two wings, and a beak. A bald eagle 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. The animals in each group have traits in common.
Scientists sort animals into groups based on traits they have in common. This process is called classification.

Solution:
A painted stork is a bird. It has feathers, two wings, and a beak.
Storks wade in shallow water to look for food. Storks eat fish, insects, worms, and other small animals.
A human is a mammal. It has hair and feeds its young milk.
Humans are a type of animal called a primate. Monkeys and apes are also primates.


Question: What is the capital of Ohio?

Choices:
- Cleveland
- Columbus
- Cincinnati
- Fargo

social science

Solution: Columbus is the capital of Ohio.


Question: Will these magnets attract or repel each other?

Choices:
- repel
- attract

natural science

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

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


Question: Which of the following could Katy and Anne's test show?

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

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.

Katy and Anne 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: Which property matches this object?

Choices:
- salty
- bendable

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 bendable object can be bent without breaking. The cracker is not bendable.
Potato chips have a salty taste. The cracker is salty.


Question: What is the capital of Vermont?

Choices:
- Montpelier
- Wilmington
- Burlington
- Hartford

social science

Identify state capitals of the Northeast

Solution: Montpelier is the capital of Vermont.


Question: Which country is highlighted?

Choices:
- Tonga
- Australia
- Solomon Islands
- New Zealand

social science

Identify and select countries of Oceania

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


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

Choices:
- copperband butterflyfish
- barracuda

Bull sharks eat turtles, birds, dolphins, and other fish. The mouth of the  is adapted to tear through meat.
Figure: bull shark.

natural science

Animal adaptations: beaks, mouths, and necks

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

Solution:
Look at the picture of the bull shark.
The bull shark has a large mouth and sharp teeth. Its mouth is adapted for tearing through meat. The bull shark uses its teeth to cut up meat into pieces it can swallow.
Now look at each animal. Figure out which animal has a similar adaptation.
The barracuda has a large mouth and sharp teeth. Its mouth is adapted for tearing through meat.
The copperband butterflyfish has a small, narrow mouth. Its mouth is not adapted for tearing through meat.


Question: Which of the following is on the map?

Choices:
- water in clouds
- water in oceans

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: 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.


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

Choices:
- zooplankton
- phytoplankton
- bat star

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

natural science

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

Solution: Use the arrows to follow how matter moves through this food web. For each answer choice, try to find a path of arrows that starts from the kelp.There is one path matter can take from the kelp to the sea cucumber: kelp->sea urchin->sea otter->orca->sea cucumber. There is one path matter can take from the kelp to the bat star: kelp->kelp bass->bat star. phytoplankton. No arrow points to the phytoplankton. So, in this food web, matter does not move from the kelp to the phytoplankton.. zooplankton. The only arrow pointing to the zooplankton starts from the phytoplankton. No arrow points to the phytoplankton. So, in this food web, matter does not move from the kelp to the zooplankton..


Question: Will these magnets attract or repel each other?

Choices:
- repel
- attract

natural science

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


Question: Select the fish below.

Choices:
- barn owl
- clownfish

Fish live underwater. They have fins, not limbs. A goldfish is an example of a fish.

natural science

Identify mammals, birds, fish, reptiles, and amphibians

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

Solution:
A barn owl is a bird. It has feathers, two wings, and a beak.
A clownfish is a fish. It lives underwater. It has fins, not limbs.


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

Choices:
- Do radishes grown under bright light get bigger than radishes grown under dim light?
- Do radish plants grown under bright light have more leaves than radish plants grown under dim light?

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

Elena planted 20 radish plants in a greenhouse, putting each plant in its own pot. She placed ten of the pots under bright light and the other ten pots under dim light. Elena watered all the plants twice a day. After two months, she pulled the radish plants from the ground, threw away the leafy green tops, and measured the sizes of the radishes. She compared the sizes of the radishes grown under bright light to the sizes of the radishes grown under dim light.
Figure: a radish plant 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: Which country is highlighted?

Choices:
- The Bahamas
- Haiti
- Cuba
- Antigua and Barbuda

social science

Identify and select countries of the Caribbean

Solution: This country is The Bahamas.


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

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

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

natural science

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

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


Question: Which property matches this object?

Choices:
- blue
- scratchy

natural science

An object has different properties. A property of an object can tell you how it looks, feels, tastes, or smells. Properties can also tell you how an object will behave when something happens to it.

Solution:
Look at the object.
Think about each property.
A scratchy object is rough and itchy against your skin. The yarn pom pom is not scratchy.
Blue is a color.
This color is blue. The yarn pom pom is blue.


Question: According to the map, which of the following statements is true about North America in the early colonial era?

Choices:
- England claimed most of the Atlantic coast of North America.
- The Dutch controlled the most territory in eastern North America.

Look at the map of North America in the early colonial era, or the 1600s and early 1700s. Then answer the question below.

social science


Question: Select the organism in the same genus as the agile wallaby.

Choices:
- Ictinia mississippiensis
- Macropus agilis
- Lacerta agilis

This organism is an agile wallaby. Its scientific name is Macropus agilis.

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:
An agile wallaby's scientific name is Macropus agilis. The first word of its scientific name is Macropus.
Ictinia mississippiensis is in the genus Ictinia. The first word of its scientific name is Ictinia. So, Ictinia mississippiensis and Macropus agilis are not in the same genus.
This organism and the agile wallaby are in the same genus and the same species! Both organisms have the same scientific name, Macropus agilis.
Lacerta agilis and Macropus agilis are not in the same genus.
These organisms are not in the same genus, but part of their scientific names is the same. Lacerta agilis and Macropus agilis have the same species name within their genus, agilis. But the first words of their scientific names are different. Lacerta agilis is in the genus Lacerta, and Macropus agilis is in the genus Macropus.


Question: What can Kyle and Tony trade to each get what they want?

Choices:
- Tony can trade his broccoli for Kyle's oranges.
- Tony can trade his almonds for Kyle's tomatoes.
- Kyle can trade his tomatoes for Tony's carrots.
- Kyle can trade his tomatoes for Tony'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.
Kyle and Tony open their lunch boxes in the school cafeteria. Neither Kyle nor Tony 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.
Kyle's lunch Tony's lunch

social science

Solution:
Look at the table and images.
Kyle wants broccoli. Tony 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: What is the capital of California?

Choices:
- Sacramento
- Boise
- Honolulu
- San Francisco

social science

Solution: Sacramento is the capital of California.


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

Choices:
- The magnitude of the magnetic force is smaller in Pair 2.
- The magnitude of the magnetic force is smaller 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 smaller when the magnets are smaller.

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


Question: Select the bird below.

Choices:
- gray tree frog
- black howler
- zebra
- barn owl

Birds have feathers, two wings, and a beak.
Birds are warm-blooded. Warm-blooded animals can control their body temperature.
A turkey 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 barn owl is a bird. It has feathers, two wings, and a beak.
Barn owls live on every continent except Antarctica.
A black howler is a mammal. It has hair and feeds its young milk.
Howler monkeys have loud calls, or howls. Their calls can be heard over three miles away!
A zebra is a mammal. It has hair and feeds its young milk.
Zebras eat mostly grass. But they sometimes eat other types of plants, such as shrubs or tree bark.
A gray tree frog is an amphibian. It has moist skin and begins its life in water.
There are many kinds of tree frogs. Most tree frogs are very small. They can walk on thin branches.


Question: What is the capital of Virginia?

Choices:
- Norfolk
- Little Rock
- Richmond
- Biloxi

social science

Identify state capitals of the Southeast

Solution: Richmond is the capital of Virginia.


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 pink 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 4 solute particles on the left side of the membrane and 2 solute particles on the right side of the membrane.
When the solute particles reached equilibrium, there were 3 solute particles on each side of the membrane. There was 1 more solute particle on the right 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 right than to the left.


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

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

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

natural science

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

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


Question: What is the capital of Idaho?

Choices:
- Salt Lake City
- Nampa
- Juneau
- Boise

social science

Solution: Boise is the capital of Idaho.


Question: What is the capital of North Carolina?

Choices:
- Charlotte
- Trenton
- Raleigh
- Oklahoma City

social science

Identify state capitals of the Southeast

Solution: Raleigh is the capital of North Carolina.


Question: Which continent is highlighted?

Choices:
- Africa
- Asia
- South America
- Antarctica

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

Choices:
- fern
- palm leaf

This diagram shows fossils in an undisturbed sedimentary rock sequence.

natural science

Compare ages of fossils in a rock sequence

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

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


Question: Which of these states is farthest south?

Choices:
- Maine
- Massachusetts
- Washington
- North Dakota

social science

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

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


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

Choices:
- climate
- weather

Figure: Obed River.
A boy floated down the Obed River on a raft. It had rained the day before, so the river was flowing fast.
Hint: Weather is what the atmosphere is like at a certain place and time. Climate is the pattern of weather in a certain place.

natural science

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

Solution:
Read the passage carefully.
A boy floated down the Obed River on a raft. It had rained the day before, so the river was flowing fast.
The underlined part of the passage tells you about the rainfall on a specific day in central Tennessee. This passage describes the atmosphere at a certain place and time. So, this passage describes the weather.


Question: Which is this organism's common name?

Choices:
- Cyprinus carpio
- common carp

This organism is Cyprinus carpio. It is also called a common carp.

natural science

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

Solution:
Cyprinus carpio is written in italics. The first word is capitalized, and the second word is not. So, it is the scientific name.
Cyprinus carpio is the organism's scientific name. So, you know that common carp is the common name.


Question: Is fruit punch a solid, a liquid, or a gas?

Choices:
- a solid
- a liquid
- a gas

natural science

Classify matter as solid, liquid, or gas

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

Solution:
Fruit punch is a liquid. A liquid takes the shape of any container it is in.
If you pour fruit punch into a cup, the punch will take the shape of the cup. But the punch will still take up the same amount of space.


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

Choices:
- Omaha
- Chicago
- St. Louis
- Cleveland

social science

Solution: The city is St. Louis, Missouri. Cleveland, Chicago, and Omaha are marked with gray circles on the map below.


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

Choices:
- Do the temperatures inside boxes depend on the sizes of the boxes?
- Do the insides of white boxes get hotter than the insides of black boxes when the boxes are left in the sun?

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

Lola glued lids onto 16 cardboard shoe boxes of equal size. She painted eight of the boxes black and eight of the boxes white. Lola made a small hole in the side of each box and then stuck a thermometer partially into each hole so she could measure the temperatures inside the boxes. She placed the boxes in direct sunlight in her backyard. Two hours later, she measured the temperature inside each box. Lola compared the average temperature inside the black boxes to the average temperature inside the white boxes.
Figure: a shoebox painted black.

natural science

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


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

Choices:
- soft
- smooth
- transparent

natural science

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

Solution:
Look at each object.
For each object, decide if it has that property.
A soft object changes shape when pressed or squeezed. All four objects are soft.
You can see clearly through a transparent object. The scarf, the stuffed dice, and the towel are not transparent.
A smooth object is not scratchy or rough. The stuffed dice and the socks are not smooth.
The property that all four objects have in common is soft.


Question: What is the capital of Oklahoma?

Choices:
- Tulsa
- Bridgeport
- Columbia
- Oklahoma City

social science

Identify state capitals of the Southeast

Solution: Oklahoma City is the capital of Oklahoma.


Question: Which country is highlighted?

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

social science

Identify and select countries of Oceania

Solution: This country is the Federated States of Micronesia.


Question: Select the mammal below.

Choices:
- koala
- mandarinfish
- bald eagle
- helmeted iguana

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

natural science

Identify mammals, birds, fish, reptiles, and amphibians

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

Solution:
A koala is a mammal. It has fur and feeds its young milk.
Koalas sleep for up to 20 hours a day!
A bald eagle is a bird. It has feathers, two wings, and a beak.
Bald eagles live in trees near water. They build nests that can be up to 13 feet wide!
A mandarinfish is a fish. It lives underwater. It has fins, not limbs.
Mandarinfish often live near coral reefs. They eat small worms, snails, and fish eggs.
A helmeted iguana is a reptile. It has scaly, waterproof skin.
Iguanas are a type of lizard. Iguanas eat plants and fruit.


Question: Which rhetorical appeal is primarily used in this ad?

Choices:
- ethos (character)
- logos (reason)
- pathos (emotion)

language science

Identify appeals to ethos, pathos, and logos in advertisements

The purpose of an advertisement is to persuade people to do something. To accomplish this purpose, advertisements use three types of persuasive strategies, or appeals.
Appeals to ethos, or character, show the writer or speaker as trustworthy, authoritative, or sharing important values with the audience. An ad that appeals to ethos might do one of the following:
say that a brand has been trusted for many years
include an endorsement from a respected organization, such as the American Dental Association
feature a testimonial from a "real person" who shares the audience's values
use an admired celebrity or athlete as a spokesperson
Appeals to logos, or reason, use logic and verifiable evidence. An ad that appeals to logos might do one of the following:
use graphs or charts to display information
cite results of clinical trials or independently conducted studies
explain the science behind a product or service
emphasize that the product is a financially wise choice
anticipate and refute potential counterclaims
Appeals to pathos, or emotion, use feelings rather than facts to persuade the audience. An ad that appeals to pathos might do one of the following:
trigger a fear, such as the fear of embarrassment
appeal to a desire, such as the desire to appear attractive
link the product to a positive feeling, such as adventure, love, or luxury

Solution: The ad appeals to ethos, or character, by emphasizing the established reputation and credibility of the brand.


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

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

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:
Complete the statement.
Hydrogen peroxide is ().

Choices:
- a compound
- an elementary substance

The model below represents a molecule of hydrogen peroxide. Hydrogen peroxide can be used to kill bacteria on medical tools.

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 peroxide is an elementary substance or a compound.
In this model, each ball is labeled with H for hydrogen or O for oxygen. So, the model shows you that hydrogen peroxide is made of two chemical elements bonded together.
Substances made of two or more chemical elements bonded together are compounds. So, hydrogen peroxide is a compound.


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

Choices:
- bouncy
- yellow
- sticky

natural science

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

Solution:
Look at each object.
For each object, decide if it has that property.
Yellow is a color.
This color is yellow. The ice pop and the wet glue are not yellow.
A bouncy object will bounce back from the floor if you drop it. None of the objects are bouncy.
A sticky object can attach or stick to other things. All three objects are sticky.
The property that all three objects have in common is sticky.


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 Illinois?

Choices:
- Springfield
- Albany
- Chicago
- Madison

social science

Solution: Springfield is the capital of Illinois.


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

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

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

natural science

Identify how particle motion affects temperature and pressure

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

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: What is the probability that a cow produced by this cross will have solid coloring?

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

In a group of cows, some individuals have solid coloring and others have white spots. In this group, the gene for the coat pattern trait has two alleles. The allele for white spots (a) is recessive to the allele for solid coloring (A).
This Punnett square shows a cross between two cows.

natural science

Use Punnett squares to calculate probabilities of offspring types

Offspring phenotypes: dominant or recessive?
How do you determine an organism's phenotype for a trait? Look at the combination of alleles in the organism's genotype for the gene that affects that trait. Some alleles have types called dominant and recessive. These two types can cause different versions of the trait to appear as the organism's phenotype.
If an organism's genotype has at least one dominant allele for a gene, the organism's phenotype will be the dominant allele's version of the gene's trait.
If an organism's genotype has only recessive alleles for a gene, the organism's phenotype will be the recessive allele's version of the gene's trait.
In a Punnett square, each box represents a different outcome, or result. Each of the four outcomes is equally likely to happen. Each box represents one way the parents' alleles can combine to form an offspring's genotype. Because there are four boxes in the Punnett square, there are four possible outcomes.
An event is a set of one or more outcomes. The probability of an event is a measure of how likely the event is to happen. This probability is a number between 0 and 1, and it can be written as a fraction:
probability of an event = number of ways the event can happen / number of equally likely outcomes
You can use a Punnett square to calculate the probability that a cross will produce certain offspring. For example, the Punnett square below has two boxes with the genotype Ff. It has one box with the genotype FF and one box with the genotype ff. This means there are two ways the parents' alleles can combine to form Ff. There is one way they can combine to form FF and one way they can combine to form ff.
 | F | f
F | FF | Ff
f | Ff | ff
Consider an event in which this cross produces an offspring with the genotype ff. The probability of this event is given by the following fraction:
number of ways the event can happen / number of equally likely outcomes = number of boxes with the genotype ff / total number of boxes = 1 / 4.


Question: 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: Identify the question that Justine and Ben's experiment can best answer.

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

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

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

natural science

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


Question: What is the capital of Utah?

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

social science

Solution: Salt Lake City is the capital of Utah.


Question: What is the capital of Iowa?

Choices:
- Tallahassee
- Cedar Rapids
- Davenport
- Des Moines

social science

Solution: Des Moines is the capital of Iowa.


Question: Which colony was Middle Colonies?

Choices:
- Connecticut
- Georgia
- New Jersey

The map below shows the Thirteen Colonies in 1750.

social science

Middle colonies: founding and government

Solution:
The four Middle Colonies are dark blue on the map:
During colonial times, Delaware was usually called the Three Lower Counties on the Delaware, or the Lower Counties for short.
New York claimed part of the land that would later become the state of Vermont. But New Hampshire, a New England colony, also claimed this area.


Question: Which statement best describes the average monthly precipitation in Atlanta?

Choices:
- February is wetter than March.
- October has the highest average precipitation.
- Precipitation does not change much from month to month in Atlanta.

Use the graph to answer the question below.

natural science

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

Solution:
To describe the average precipitation trends in Atlanta, look at the graph.
Choice "Feb" is incorrect.
Choice "Mar" is incorrect.
Choice "Oct" is incorrect.
Choice "Precipitation does not change much from month to month in Atlanta." is incorrect.
The average monthly precipitation changes only slightly throughout the year.
Choice "February is wetter than March." is incorrect.
Wetter months have a higher average precipitation than drier months. February has a slightly lower average monthly precipitation than March. So, February is not wetter than March.
Choice "October has the highest average precipitation." is incorrect.
Most other months have a slightly higher average precipitation than October.


Question: What is the capital of West Virginia?

Choices:
- Charleston
- Huntington
- Baton Rouge
- Richmond

social science

Identify state capitals of the Southeast

Solution: Charleston is the capital of West Virginia.


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

Choices:
- climate
- weather

Figure: Vancouver Island.
Vancouver Island is in on the west coast of Canada. Much of the island received heavy rain on November 28 last year.
Hint: Weather is what the atmosphere is like at a certain place and time. Climate is the pattern of weather in a certain place.

natural science

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

Solution:
Read the passage carefully.
Vancouver Island is in on the west coast of Canada. Much of the island received heavy rain on November 28 last year.
The underlined part of the passage tells you about the amount of rain that fell in Vancouver Island on November 28. This passage describes the atmosphere at a certain place and time. So, this passage describes the weather.


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


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

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 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: Will these magnets attract or repel each other?

Choices:
- repel
- attract

Two magnets are placed as shown.

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

natural science

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

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


Question: What can Rob and Carrie trade to each get what they want?

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

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.
Rob and Carrie open their lunch boxes in the school cafeteria. Both of them could be happier with their lunches. Rob wanted broccoli in his lunch and Carrie was hoping for tomatoes. Look at the images of their lunches. Then answer the question below.

social science

Solution:
Rob wanted broccoli in his lunch and Carrie was hoping for tomatoes. Look at the labeled part of the images.
Rob has tomatoes. Carrie 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: Select the chemical formula for this molecule.

Choices:
- PCl5N
- PCl5
- P2Cl6
- Cl6

natural science

Match chemical formulas to ball-and-stick models

Every substance around you is made up of atoms. Atoms can link together to form molecules. The links between atoms in a molecule are called chemical bonds. Different molecules are made up of different chemical elements, or types of atoms, bonded together.
Scientists use both ball-and-stick models and chemical formulas to represent molecules.
A ball-and-stick model of a molecule is shown below.
The balls represent atoms. The sticks represent the chemical bonds between the atoms.
Notice how each ball is labeled with a symbol made of one or more letters. The symbol is an abbreviation for a chemical element. The ball represents one atom of that element.
Every chemical element is represented by its own symbol. For some elements, that symbol is one capital letter. For other elements, it is one capital letter followed by one lowercase letter. For example, the symbol for the element boron is B and the symbol for the element chlorine is Cl.
The molecule shown above has one boron atom and three chlorine atoms. A chemical bond links each chlorine atom to the boron atom.
The chemical formula for a molecule contains the symbol for each chemical element in the molecule. Many chemical formulas use subscripts. A subscript is text that is smaller and placed lower than the normal line of text.
In chemical formulas, the subscripts are numbers. The subscript is always written after the symbol for an element. The subscript tells you how many atoms that symbol represents. If the symbol represents just one atom, then no subscript is included.
The symbols in the chemical formula for a molecule match the symbols in the ball-and-stick model for that molecule. The ball-and-stick model shown before and the chemical formula shown above represent the same substance.

Solution:
P is the symbol for phosphorus. Cl is the symbol for chlorine. This ball-and-stick model shows a molecule with one phosphorus atom and five chlorine atoms.
The chemical formula will contain the symbols P and Cl. There is one phosphorus atom, so P will not have a subscript. There are five chlorine atoms, so Cl will have a subscript of 5.
The correct formula is PCl5.
The diagram below shows how each part of the chemical formula matches with each part of the model above.


Question: Which air temperature was measured within the outlined area shown?

Choices:
- 30°C
- 14°C
- 10°C

The map below shows air temperatures in the lower atmosphere on October 1, 2015. The outlined area shows an air mass that influenced weather in North America on that day.
Look at the map. Then, answer the question below.
Data source: United States National Oceanic and Atmospheric Administration/Earth System Research Laboratory, Physical Sciences Division

natural science

To study air masses, scientists can use maps that show conditions within Earth's atmosphere. For example, the map below uses color to show air temperatures.
The map's legend tells you the temperature that each color represents. Colors on the left in the legend represent lower temperatures than colors on the right. For example, areas on the map that are the darkest shade of blue have a temperature from -25°C up to -20°C. Areas that are the next darkest shade of blue have a temperature from -20°C up to -15°C.

Solution:
Look at the colors shown within the outlined area. Then, use the legend to determine which air temperatures those colors represent.
The legend tells you that this air mass contained air with temperatures between 25°C and 35°C.
30°C is within this range.
10°C and 14°C are outside of this range.


Question: What is the capital of Alaska?

Choices:
- Juneau
- Dover
- Salt Lake City
- Atlanta

social science

Solution: Juneau is the capital of Alaska.


Question: What is the capital of South Dakota?

Choices:
- Rapid City
- Sioux Falls
- Pierre
- Montgomery

social science

Solution: Pierre is the capital of South Dakota.


Question: What is the capital of Idaho?

Choices:
- Fairbanks
- Santa Fe
- Boise
- Nampa

social science

Solution: Boise is the capital of Idaho.


Question: Is the air inside a bubble a solid, a liquid, or a gas?

Choices:
- a liquid
- a gas
- a solid

natural science

Classify matter as solid, liquid, or gas

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

Solution:
The air inside a bubble is a gas. A gas expands to fill a space.
The air inside a bubble fills all the space in the bubble. If the bubble pops, the air will expand to fill a much larger space.


Question: Select the reptile below.

Choices:
- California toad
- Hermann's tortoise

Reptiles have scaly, waterproof skin. Most reptiles live on land. An American alligator is an example of a reptile.

natural science

Identify mammals, birds, fish, reptiles, and amphibians

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

Solution:
A California toad is an amphibian. It has moist skin and begins its life in water.
Toads do not have teeth! They swallow their food whole.
A Hermann's tortoise is a reptile. It has scaly, waterproof skin.
A tortoise's shell protects it from predators. When a tortoise feels threatened, it can pull its head and legs inside its shell.


Question: Select the fish below.

Choices:
- manta ray
- giraffe

Fish live underwater. They have fins, not limbs. A piranha is an example of a fish.

natural science

Identify mammals, birds, fish, reptiles, and amphibians

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

Solution:
A manta ray is a fish. It lives underwater. It has fins, not limbs.
Rays have a different shape than many other fish. Rays are large and flat. They have wide, triangle-shaped fins that help them swim long distances.
A giraffe is a mammal. It has hair and feeds its young milk.
Giraffes eat mostly leaves that are too high up for other animals to reach.


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

Choices:
- shiny
- fuzzy
- transparent

natural science

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

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


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

Choices:
- Do cardinals eat more seeds per visit from feeders containing sunflower seeds compared to feeders containing flax seeds?
- Do cardinals visit feeders containing sunflower seeds more often than feeders containing flax seeds?

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

Winston set up five pairs of platform bird feeders around his yard. He filled one feeder in each pair with sunflower seeds and the other feeder with flax seeds. For one week, Winston watched cardinals visiting the feeders during the same hour each morning. During his observations, Winston counted the number of visits by cardinals to feeders with sunflower seeds and the number of visits by cardinals to feeders with flax seeds.
Figure: a cardinal visiting a platform feeder with sunflower seeds.

natural science

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


Question:
Is the following statement about our solar system true or false?
50% of the planets are made mainly of gas.

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 two out of the eight planets are made mainly of gas. So, one-fourth, or 25%, of the planets are made mainly of gas.


Question: What is the expected ratio of offspring with black eyes to offspring with red eyes? Choose the most likely ratio.

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

In a group of koi fish, some individuals have red eyes and others have black eyes. In this group, the gene for the eye color trait has two alleles. The allele for red eyes (E) is dominant over the allele for black eyes (e).
This Punnett square shows a cross between two koi fish.

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 black eyes or red eyes, consider whether each phenotype is the dominant or recessive allele's version of the eye color trait. The question tells you that the E allele, which is for red eyes, is dominant over the e allele, which is for black eyes.
Black eyes is the recessive allele's version of the eye color trait. A koi fish with the recessive version of the eye color trait must have only recessive alleles for the eye color gene. So, offspring with black eyes must have the genotype ee.
There are 0 boxes in the Punnett square with the genotype ee.
Red eyes is the dominant allele's version of the eye color trait. A koi fish with the dominant version of the eye color trait must have at least one dominant allele for the eye color gene. So, offspring with red eyes must have the genotype EE or Ee.
All 4 boxes in the Punnett square have the genotype EE or Ee.
So, the expected ratio of offspring with black eyes to offspring with red eyes is 0:4. This means that, based on the Punnett square, this cross will never produce offspring with black eyes. Instead, this cross is expected to always produce offspring with red eyes.