Biomes and Aquatic Ecosystems

Many biologists consider the polar bear a marine mammal rather than a land mammal. What is one possible reason for this?

polar bears spend much of their time on ice or in the ocean

The tropical rain forest biome supports dense forests. However, if the forests are cut down, the land may become barren. Why is this?

the soil is thin and low in nutrients

Which of the following is a characteristic of tropical rain forest?

thin soil that is low in nutrients

Why are there fewer trees in tropical grasslands than in tropical rain forests?

tropical grasslands have a long dry season

The uppermost layer of branches in rain forest trees is called

Canopy

The main factor that determines what type of plants grow in a biome is

Temperature and precipation

Why is the tundra sometimes considered a semidesert?

There is little precipitation

How would coral reefs likely be affected if global ocean temperatures increased slightly?

They would decline

Trees that drop their leaves during the cold season are known as

deciduous trees

A plant with small leaves and long roots is most likely adapted to live in which biome?

desert

Estuaries are...

ecosystems where both fresh and salt water are present

Communities on a mountain differ depending on the

elevation

Estuary ecosystems are important to humans as a source of

fish for food

Just before you reach the top of a mountain where there is year-round ice and snow, you would expect to se

herbs, lichens, and mosses

Plants and animals that live in savannas are well-adapted to

large changes in moisture

Why are estuaries often call nurseries of the sea?

many species use them as spawning grounds

What are the two main types of freshwater wetlands?

marshes and swamps

Where is the tropical zone?

surrounding the equator

Animals such as pronghorn antelope, bison, and badgers dot the landscape. Where are these animals located?

the North American prairie