Question

1. marine ecosystems at the poles are unusual because

a. animals spend time both in and out of the water.
b. plankton are rare.
c. they contain ice.
d. the salt content of the water is very high.

1. the major factor that determines the types of organisms that live in a stream or river is

a. the water temperature.
b. the speed of the current.
c. the depth of the water.
d. the width of the stream or river.

1. marine ecosystems

a. contain the largest animals in the world.
b. exist in all ocean zones.
c. include environments where organisms survive without light.
d. all of the above

1. two major factors that determine what kind of a biome is found in a region are

a. the amount of rainfall and the temperature.
b. the depth of water and the distance from land.
c. the wave action and the salt content of the water.
d. all of the above

Explanation:

1. Marine ecosystems at the poles are unusual mainly due to the presence of ice. Ice - covered conditions affect the habitat, food - web, and other ecological aspects.
2. The speed of the current is a major factor determining the types of organisms in a stream or river as it affects water flow, oxygen availability, and the ability of organisms to attach or move.
3. Marine ecosystems contain the largest animals (like blue whales), exist in all ocean zones (from intertidal to abyssal), and have environments where organisms survive without light (in deep - sea zones).
4. The amount of rainfall and temperature are the two major factors determining the type of biome in a region as they influence plant growth and thus the entire ecosystem.

Answer:

1. c. they contain ice.
2. b. the speed of the current.
3. d. All of the above
4. a. the amount of rainfall and the temperature.