Healthy Habitat

Read this sentence from paragraph 3 of "The Key to a Healthy Habitat."

Large herds of spiky sea urchins have been known to destroy whole kelp forests, leaving an underwater wasteland.

The author's word choice in this sentence is used to -

• A. imply that water becomes scarce

• B. show that an area was completely devastated

• C. reveal the quantity fo sea urchins needed

• D. suggest delayed growth of kelp

Which detail from paragraph 4 of "The Key to a Healthy Habitat" reveals the author's viewpoint about keystone species that modify their habitats?

• A. benefit other species in the ecosystem they share

• B. create wetlands with ponds and marshes

• C. live underground in large colonies

• D. provide shelter for other animals

Which detail should be included in a summary of "How Keystone Species Create Balance" section of "The Key to a Healthy Habitat"?

• A. Yellowstone was made into a national park before wolves were removed.

• B. Wolves prey on elk, and elk eat grass at Yellowstone.

• C. Bison, birds, and small mammals are all part of the Yellowstone ecosystem.

• D. Yellowstone is an ecosystem that experienced damage and was restored.

Read this sentence from paragraph 2 of "Keystones."

The keystone is the one piece that is critical to the success of the whole structure.

Identify which ideas from "The Key to a Healthy Habitat" support or do not support the author's idea in this sentence.

• Supports

• Flowers produce nectar.

• Supports

• Prairie dogs make tunnels.

• Does not support.

• Trees grow taller.

In "The Key to a Healthy Habitat," the diagram best supports which three ideas from paragraph 3?

The main point developed in paragraphs 1-3 of "the Key to a Healthy Habitat" is that a keystone species differs from other species because it -

• A. belongs in an ecosystem's food web

• B. consumes other organisms

• C. manages an ecosystem's health

• D. increases rapidly in population size

In paragraph 7 of "the Key to a Healthy Habitat," which effects does the author suggest are evidence or are not evidence that the ecosystem is in danger?

• Not Evidence

• An increase in erosion

• Evidence

• The loss of plant life

• Evidence

• Removal of grazing animals

Read this sentence from paragraph 6 of "The Key to a Healthy Habitat."

Lose a keystone species, and big changes follow.

Which detail from "The Key to a Healthy Habitat" does the author include to show a result of losing a keystone species?

• A. Mussels then crowded out other species and destroyed the diversity in the pools.

• B. Some animals are keystone species because of how they modify their habitats

• C. This occurs when two or more species rely on their relationship to survive

• D. A certain animal can be a keystone species in one area but not in another

"Keystones" explains what happens to an arch without a keystone. Which sentence from "The Key to a Healthy Habitat" does its author include to convey a similar message?

• A. Paine concluded that sometimes one species can have a greater influence on its environment than other species do.

• B. Some animals eat the plans, and various predators eat the animals that eat the plants.

• C. However, removal of the wolves led to a huge increase in the populations of animals that survive by grazing on vegetation.

• D. Plants regrew, birds and mammals returned, trees began to mature.