The diagram below shows the relationships among organisms living in an Atlantic coast estuary. Use the diagram to answer the following.

Which of these best describes the role of the blue crab in the estuary ecosystem?

The diagram below shows the relationships among organisms living in an Atlantic coast estuary. Use the diagram to answer the following.

The croaker, menhaden, and striped bass are fished for food. Which of these graphs shows how a decrease in the fish populations would most likely affect the copepod population?

Use the diagram of the marine food web below to answer the following.

Which of these best describes the role of the krill in this food web?

Use the technical passage below to answer the following.

Scientists Explore An Aspect of Fish Migration

In addition to eating fish eggs, the arctic grayling also eats insects and small fish. What is the ecological role of the arctic grayling?

A team of scientists conducted a study of a wetland. Using samples collected from the wetland, the scientists estimated the total biomass at each trophic level. Their data are shown below.

Explain the relationship between trophic levels and biomass. In your response, be sure to include

• the roles of the organisms found at the different trophic levels
• how each trophic level obtains energy
• why the available energy changes at each level
• why the amount of mass differs at each of the trophic levels

Write your answer in your Answer Book.

Use the information and the food web below to answer the following.

A marine environment provides a habitat for a variety of plants and animals. A small part of a marine food web is shown below.

Which of these describes the role of the sanderling in the marine food web?

The energy pyramid below shows the flow of energy through the organisms in a kelp forest ecosystem in the Pacific Ocean. Use the energy pyramid to answer the following.

What is the lowest level of the energy pyramid that contains carnivores?

A team of marine scientists is studying biotic and abiotic factors that affect the stability of a deep-sea ecosystem.

The scientists discovered a species of fish that eats other fish and decaying matter. Which of these does not describe the newly discovered fish?

A team of marine scientists is studying biotic and abiotic factors that affect the stability of a deep-sea ecosystem.

The deep-sea ecosystem is a stable ecosystem. Which of these is a characteristic of most stable ecosystems?

Scientists have recently discovered hydrothermal vent communities on the ocean floor. A diagram of a hydrothermal vent community is shown in the figure below.

The organisms in this community live near heated vents. Inorganic compounds such as sulfides mix with extremely hot water when they are released from the vents. Bacteria use the sulfides to make food for themselves and other animals. Many of these bacteria live in the bodies of the giant tubeworms and the giant white clams that live in this community.

Hydrothermal vent communities are often destroyed by lava erupting from the ocean floor. After the lava has cooled, different organisms begin to inhabit the area. Over a period of a few years, organisms inhabit the area in the following order:

sulfur bacteria -> crabs -> giant tubeworms -> clams and mussels

Which of these best identifies this sequence of events?

Part of the food web in Yellowstone National Park is shown below.

Gray wolves were reintroduced into Yellowstone National Park in 1995. Two years later, the population of coyotes had decreased by 50%. Coyotes were found in all habitats of the park before the gray wolves were reintroduced. Now, coyotes are most often found in the hills and mountains.

Which of these describes the role of the vole in the Yellowstone ecosystem?

Use the diagram of the marine food web below to answer the following.

Which of these best describes the relationship between the phytoplankton and zooplankton?

Scientists classify humans as omnivores, based on their teeth. As omnivores, humans eat

An ecosystem contains organisms interacting with each other and their physical environment. Which of these is the best indicator of a healthy ecosystem?

Biologists conducted a study on the population sizes of a species of snail and a species of algae found in a lake ecosystem. The results of their study are shown in the graph below.

Based on the data in the graph, explain the most likely relationship between the two species. In your response, be sure to

• identify the ecological role of the snails and the algae
• identify the trophic level each species occupies
• explain the ecological factors that may affect the population size of the two species
• explain how both populations would be affected if a landfill for garbage were built on the land surrounding the lake

Write your answer in your Answer Book.

Which of these describes the role of the red oak in the forest food web?

Use the technical passage “Exotic Species Versus Native Species, Who’s Winning?” to answer the following:

Eco-invasion of an area will most likely result in

Use the relationships in the food web below to answer the following question.

According to the food web, which of these supply energy for all the other organisms?

Some of the relationships among organisms living in a wetland are shown in the figure below.

Describe the flow of energy in the wetland food web. In your response, be sure to

• name the biotic and abiotic factors affecting the heron
• identify the trophic levels of the different organisms in the wetland food web
• describe how the energy is transferred between the organisms in the wetland food web
• explain how the other organisms in the wetland ecosystem would be affected by the sudden disappearance of the heron population

Write your answer in your Answer Book.

Use the technical passage below to answer Numbers 32 and 33.

Use the technical passage to answer the following item.

What is the ecological role of the black bear?

Students are building an exhibit of an East African food web for a science fair. The food web they are using is shown below.

Analyze the roles of the organisms and the flow of energy in the East African food web. In your response, be sure to

• identify the role of each organism in the food web
• describe the relationship among the organisms in the ecosystem
• explain how a pyramid can be used to show the relationship among the organisms in the food web
• explain how the organisms in this food web would best fit in a pyramid model

Write your answer in your Answer Book.

Use the information and the figure below to answer the following item.

Many plants that grow in tropical rain forests have specialized roots that anchor them to the branches and trunks of trees. They do not harm the trees. These plants get food and water from various sources, including the air and dead organic matter found on the trees.

One example of these plants found in tropical rain forests is the bromeliad. Its leaves form a cup-like structure that is able to hold water. This water provides a feeding and breeding area for many insects and frogs. Snakes and lizards also come to these plants in search of food and water. A cross-section showing the inside of a bromeliad is shown below.

Which of these types of organisms break down dead organic matter in the rain forest?

Use the information and the figure below to answer the following item.

Many plants that grow in tropical rain forests have specialized roots that anchor them to the branches and trunks of trees. They do not harm the trees. These plants get food and water from various sources, including the air and dead organic matter found on the trees.

One example of these plants found in tropical rain forests is the bromeliad. Its leaves form a cup-like structure that is able to hold water. This water provides a feeding and breeding area for many insects and frogs. Snakes and lizards also come to these plants in search of food and water. A cross-section showing the inside of a bromeliad is shown below.

Which of these terms best describes the wide variety of plant and animal species in the rain forest?

Use the information below to answer the following item.

Scientists genetically modified a variety of corn to protect it against pests like the corn borer. The corn borer is an insect caterpillar that feeds on the corn stalk, which weakens the stalk and makes it fall over. A new gene in the genetically modified corn causes the plant to produce a chemical that is toxic to the corn borer. Some people are concerned that the genetically modified corn could harm other insects such as the monarch butterfly caterpillar. The monarch caterpillar eats leaves of milkweed plants that might be coated with toxic corn pollen. However, not all researchers agree with the concerns regarding the monarch butterfly caterpillar. They state that it is unusual for large amounts of harmful corn pollen to be found on milkweed leaves. Also, only a small percentage of caterpillars feed on the milkweed plants near corn fields.

Which of these describes the trophic level of the corn borer?

Use the information below to answer Numbers 39 and 40.

Use the information below to answer the following item.

Many bird species in the forests of eastern North America have very large geographic ranges. Bird species in tropical forests have very small geographic ranges. Many forest areas within the ranges of these birds are being destroyed. Scientists believe that the destruction of forests affects birds with small ranges more than birds with large ranges.

As a result of the destruction of forests, birds with a small geographic range are most likely to

Use the information below to answer the following item.

In an ocean environment, marine life is most abundant in the euphotic zone. This zone extends from the surface waters to a depth of 200 meters, the deepest depth that sunlight can reach. It is in this range that phytoplankton capture energy from the sun. Although they are microscopic organisms, phytoplankton are the foundation that supports the marine food web.

Which trophic level is most likely missing from an ocean floor food web at a depth of 800 meters?

Use the technical passage and drawing to answer the following item.

Some marshes and swamps eventually become homes to communities that include mature trees. What is this process called?