Nitrogen cycle

Organisms that need nitrogen to survive.

• only plants

• only animals

• only bacteria

• all living things

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

• Through action of bacteria only

• Through lightning only

• Through action of bacteria and lightning

• Through photosynthesis

How do animals get the nitrogen they need?

• From the air they breathe

• From the water they drink

• From the food they eat

• From the sun

Gas that makes up 78% of our atmosphere.

• Oxygen

• Nitrogen

• Hydrogen

• Carbon Dioxide

What is the formula for atmospheric nitrogen?

• N

• N₂

• NH₃

• NO₃

According to this diagram, plants use nitrogen to make _________________________

• bacteria

• animals

• proteins

• decomposers

According to this diagram, plants absorb

• nitrates

• nitrogen fixing bacteria

• animals

• decomposers

The process that allows organisms to use nitrogen

• assimilation

• denitrification

• fixation

• ammonification

A correct path that nitrogen could take would be

• air -> animals -> plants -> bacteria

• animals -> air -> bacteria -> plants

• bacteria -> air -> plants -> animals

• air -> bacteria -> plants -> animals

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

• Gas

• Clouds

• Carbon dioxide in the atmosphere

• Nitrogen in the atmosphere