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nitrogen cycle

Total questions: 20

Worksheet time: 18mins

Name
Class
Date
1.

Where can nitrogen fixing bacteria be found (2 right answers)

a)

Free living in the soil

b)

under the leaves of flowering plants

c)

in the atmosphere

d)

living on the nodules of certain plants

2.

This can transform nitrogen in the atmosphere into a usable form of nitrogen

a)

rain

b)

ice

c)

lightning

d)

sun

3.

True or False. The nitrogen in the atmosphere is in the right form for living things to use.

a)

True

b)

False

4.
How much of the atmosphere is composed of nitrogen gas?
a)
87%
b)
38%
c)
78%
d)
21%
5.

In the nitrogen cycle, what does label A in the diagram represent?

a)

Gas

b)

Clouds

c)

Carbon dioxide in the atmosphere

d)

Nitrogen in the atmosphere

6.

Bacteria create a form of nitrogen that animals can use directly.

a)

True

b)

False

7.

Bacteria fix nitrogen from the atmosphere into a form plants can use.

a)

True

b)

False

8.

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

9.

The process that allows organisms to use nitrogen

a)

assimilation

b)

denitrification

c)

fixation

d)

ammonification

10.

According to this diagram, animals get proteins from eating ________________________

a)

decomposers

b)

bacteria

c)

plants

d)

sunlight

11.

According to this diagram, plants absorb

a)

nitrates

b)

nitrogen fixing bacteria

c)

animals

d)

decomposers

12.

According to this diagram, plants use nitrogen to make _________________________

a)

bacteria

b)

animals

c)

proteins

d)

decomposers

13.

What process occurs when dead plant and animal matter decomposes and nitrogen is released back into the atmosphere?

a)

Assimilation

b)

Fixation

c)

Ammonification

d)

Denitrification

14.

What is the formula for atmospheric nitrogen?

a)

N

b)

N2

c)

NH3

d)

NO3

15.

Gas that makes up 78% of our atmosphere.

a)

Oxygen

b)

Nitrogen

c)

Hydrogen

d)

Carbon Dioxide

16.

How do animals get the nitrogen they need?

a)

From the air they breathe

b)

From the water they drink

c)

From the food they eat

d)

From the sun

17.

How is nitrogen "fixed" into a usable form for plants?

a)

Through action of bacteria only

b)

Through lightning only

c)

Through action of bacteria and lightning

d)

Through photosynthesis

18.

Organisms that need nitrogen to survive.

a)

only plants

b)

only animals

c)

only bacteria

d)

all living things

19.

The process in which nitrogen circulates and is recycled is called

a)

The nitrogen cycle

b)

The carbon cycle

c)

The water cycle

d)

The phosphorus cycle

20.

What converts nitrogen gas into a usable form for plants and animals?

a)

bacteria

b)

rain

c)

fungi

d)

car exhaust