Question

chapter 12 mastery test a, continued
part c number the steps in each cycle in order.

1. water cycle

____ water evaporates into atmosphere.
____ rainfall fills lakes, rivers, oceans.
____ water vapor cools; clouds form.

1. nitrogen cycle

____ nitrogen gas is in the air.
____ an animal dies and is decomposed.
____ animals get nitrogen by feeding on plants.
____ bacteria change nitrogen gas into ammonia and nitrates plants can use.

1. carbon cycle

____ animals eat plants, taking in carbon.
____ living things give off carbon dioxide as they respire.
____ plants take in carbon dioxide from air.
part d write the answers to the following questions on the blanks.

1. what is ecology?

____

1. what is the role of decomposers in a community?

____

1. over a long period of succession, what kind of community is established?

____

1. what is a food web?

____

1. why should nonrenewable resources by conserved, or saved?

____

1. how do organisms return carbon to the atmosphere?

____

1. why are there large populations of organisms low on the pyramid of numbers?

____
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Explanation:

1. Water cycle steps: First, water evaporates into atmosphere (3). Then water vapor cools; clouds form (2). Rainfall fills lakes, rivers, oceans (1).
2. Nitrogen cycle steps: Nitrogen gas is in the air (1). Bacteria change nitrogen gas into ammonia and nitrates plants can use (4). Animals get nitrogen by feeding on plants (3). An animal dies and is decomposed (2).
3. Carbon cycle steps: Plants take in carbon dioxide from air (1). Animals eat plants, taking in carbon (2). Living things give off carbon dioxide as they respire (3).
4. Ecology is the study of the relationships between living organisms and their environment.
5. Decomposers break down dead organisms and waste materials, recycling nutrients back into the ecosystem.
6. A climax community is established over a long - period of succession.
7. A food web is a complex network of interconnected food chains in an ecosystem.
8. Nonrenewable resources should be conserved because they are finite and cannot be replenished quickly.
9. Organisms return carbon to the atmosphere through respiration.
10. There are large populations of organisms low on the pyramid of numbers because they form the base of the energy pyramid and support higher - level organisms.

Answer:

1. 3, 2, 1
2. 1, 4, 3, 2
3. 1, 2, 3
4. The study of the relationships between living organisms and their environment.
5. Break down dead organisms and waste materials, recycle nutrients.
6. Climax community.
7. A complex network of interconnected food chains in an ecosystem.
8. Because they are finite and cannot be replenished quickly.
9. Through respiration.
10. They form the base of the energy pyramid and support higher - level organisms.