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Nitrogen and Carbon Cycle

Total questions: 20

Worksheet time: 14mins

Name
Class
Date
1.
Which of the following add carbon dioxide to the atmosphere?
a)
volcanoes
b)
combustion of fossil fuels
c)
animal and plant respiration
d)
all of these
2.
What is happening at 1?
a)
respiration: releasing CO2
b)
decomposing CO2 in the soil
c)
photosynthesis: absorbing CO2
d)
turning CO2 from the atmosphere into organic molecules
3.
How much of the atmosphere is composed of nitrogen gas?
a)
87%
b)
38%
c)
78%
d)
21%
4.
Why do all organisms need nitrogen?
a)
To live and grow 
b)
To build phosphorus
c)
To make oxygen levels grow
d)
To help blood circulate better
5.
Nitrogen fixing bacteria, lives in nodules on the root of a plant called
a)
Broccoli
b)
Legumes
c)
Beats
d)
Carrots
6.
How nitrogen is "fixed" into useable form for plants
a)
only through action of bacteria
b)
only through lightning
c)
through action of bacteria & lightning
d)
through photosynthesis
7.
When humans burn fossil fuels, most of the carbon quickly enters the                       as carbon dioxide.
a)
Water
b)
Atmosphere
c)
Sun
d)
Air
8.
TRUE or FALSE?
All of the carbon in existence is continually recycled in the carbon cycle.
a)
True
b)
False
9.

Which describes the relationship between plants and animals in the carbon cycle?

a)

Plants produce and release oxygen that animals need

b)

Plants produce and release carbon dioxide that animals need

c)

Animals produce and release oxygen that plants need

d)

Animals produce oxygen that plants turn into carbon dioxide

10.
How do  animals get nitrogen?
a)
the atmosphere 
b)
eating other organisms
c)
bacteria
d)
lightning 
11.
Building proteins and DNA is the reason organisms need what substance?
a)
Water
b)
Carbon
c)
Nitrogen
d)
Calcium
12.
What is the role of decomposers in an Ecosystem? 
a)
They recycle matter and nutrients to form fossil fuels
b)
They are burn and release as carbon dioxide
c)
Decomposers are responsible to turn oxygen into carbon dioxide
d)
They recycle energy back to the sun
13.
Organisms that play a role in the nitrogen cycle
a)
only plants
b)
only animals
c)
only bacteria
d)
plants, animals, & bacteria
14.
When nitrogen gas is turned in to a form that plants and animals can use is called 
a)
Combustion
b)
Photosynthesis
c)
Decomposition
d)
Nitrogen Fixation
15.
What converts nitrogen into a useable form for plants and animals?
a)
bacteria
b)
fungi
c)
rain
16.
Identify the cycle pictured.
a)
The Water cycle
b)
The Carbon cycle
c)
The Nitrogen cycle
d)
The Phosphorus cycle
17.
Identify the cycle pictured.
a)
The Water cycle
b)
The Carbon cycle
c)
The Nitrogen cycle
d)
The Phosphorus cycle
18.

Plants use carbon dioxide in the process of _____________.

a)

decay

b)

shedding leaves

c)

photosynthesis

d)

respiration

19.

A correct path that nitrogen could take would be

a)

air -> animals -> plants -> bacteria

b)

animals -> air -> bacteria -> plants

c)

bacteria -> air -> plants -> animals

d)

air -> bacteria -> plants -> animals

20.

What is denitrification?

a)

Conversation of nitrite back to nitrogen gas

b)

Conversation of ammonia back to nitrogen gas