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Worksheets

Carbon and Nitrogen Cycles

Total questions: 20

Worksheet time: 10mins

Name
Class
Date
1.

What process converts nitrogen gas into a biologically useful (fixed) form?

a)

Respiration

b)

Assimilation

c)

Denitrification

d)

Nitrogen fixation

2.

Which organisms play the largest role in converting nitrogen into various usable forms and back to a gas form?

a)

rabbits

b)

bacteria

c)

plants

d)

worms

3.

How do animals get nitrogen to make important biological molecules?

a)

Breathe it in through the air

b)

Fix it from nitrogen gas

c)

Consume other organisms

d)

Assimilate it through the soil

4.

Which of the following cannot fix nitrogen?

a)

lightning

b)

fertilizer production

c)

combustion

d)

rain

5.

Which of the following is not a possible process that results in ammonification?

a)

photosynthesis

b)

decomposition

c)

nitrogen fixation

d)

fertilizer production

6.

Carbon moves between which two reservoirs through the process of diffusion?

a)

atmosphere & biosphere

b)

atmosphere & lithosphere

c)

lithosphere & biosphere

d)

hydrosphere & atmosphere

7.

What happens to carbon during the process of photosynthesis?

a)

CO2 is released by plants

b)

CO2 is taken up by plants

c)

organic carbon is taken up through plant roots

d)

carbon is lost through heat

8.

All the gases surrounding Earth are known collectively as the...

a)

hydrosphere

b)

biosphere

c)

atmosphere

d)

lithosphere

9.

The process of breathing in oxygen and releasing carbon dioxide into the air (or water) is...

a)

Assimilation

b)

Decomposition

c)

Photosynthesis

d)

Respiration

10.

Which of the following best describes weathering and erosion?

a)

when it rains on rocks

b)

decay of dead organisms

c)

break down of rocks that wash into the water

d)

when a volcano erupts

11.

Which of the following best describes the Greenhouse Effect?

a)

when solar radiation reflects off the atmosphere

b)

heat is retained in Earth's atmosphere by greenhouse gases

c)

plants grow better when a greenhouse is filled with CO2

d)

when solar radiation hits Earth's surface directly

12.

Which gas is most abundant in the atmosphere?

a)

carbon dioxide

b)

methane

c)

nitrous oxide

d)

nitrogen gas

13.

Which of the following does NOT release carbon dioxide into the atmosphere?

a)

volcanic activity

b)

respiration

c)

photosynthesis

d)

fossil fuel combustion

14.

The most abundant Greenhouse Gas in the atmosphere is...

a)

carbon dioxide

b)

nitrogen gas

c)

nitrate

d)

oxygen

15.

The process of making nitrites and nitrates is...

a)

denitrification

b)

nitrogen fixation

c)

nitrification

d)

ammonification

16.

What does denitrification do?

a)

converts fixed nitrogen into nitrogen gas

b)

converts nitrogen gas into fixed nitrogen

c)

makes nitrates

d)

makes ammonia

17.

Which of the following is not a form of fixed nitrogen?

a)

ammonia

b)

nitrogen gas

c)

nitrate

d)

nitrite

18.

Which of the following best describes the movement of nitrogen between reservoirs in the process of assimilation?

a)

from the soil into plants

b)

from the air into plants

c)

from the air into soil

d)

from soil into animals

19.

The process that releases carbon and nitrogen into the soil through decay is...

a)

erosion

b)

photosynthesis

c)

decomposition

d)

assimilation

20.

Which of the following would not be included in the hydrosphere?

a)

ocean

b)

trees

c)

surface water

d)

groundwater