Lesson 58: The Nitrogen Cycle

The conversion of atmospheric nitrogen into ammonia, a form of nitrogen plants can readily use, is called -

• denitrification.

• ammonification.

• nitrogen fixation.

• nitrification.

Tags

NGSS.MS-LS2-3

To obtain the nitrogen they need, animals depend on many different microscopic ____________________ to convert nitrogen at all stages of the nitrogen cycle.

• protozoa

• bacteria

• worms

• insects

Denitrifying, anaerobic bacteria convert nitrate into nitrogen gas that returns to the atmosphere. What does anaerobic refer to?

• Oxygen is present.

• Oxygen is not present.

• There is little or no light available.

• There are several species of bacteria.

Tags

NGSS.HS-LS2-3

The atmosphere is made up of mostly nitrogen. The percentage of nitrogen in the atmosphere is approximately _____.

• 60%

• 78%

• 83%

• 51%

Decomposers make ammonium in the soil during the process of -

• nitridication.

• nitrogen fixation.

• denitrification.

• ammonification.

Tags

NGSS.MS-LS2-3

____________________ converts ammonia and ammonium into nitrite and nitrate.

Tags

NGSS.MS-LS2-3

Ammonia and ammonium are compounds of -

• nitrogen and hydrogen.

• nitrogen and oxygen.

• hydrogen and oxygen.

• oxygen and chlorine.

Tags

NGSS.MS-PS1-1

Select all answers below that are stages of the nitrogen cycle.

• Nitrogen fixation

• Diffusion

• Ammonification

• Nitrification

Tags

NGSS.MS-LS2-3

The relationship between some plants and nitrogen-fixing bacteria is -

• predator-prey.

• parasitic.

• mutualistic.

• commensal.

Tags

NGSS.MS-LS2-3

The nitrogen cycle converts _________________ nitrogen into a useful form that living organisms can use to build proteins and nucleic acids within their cells.

• cellular

• atnospheric

• soil-based

• anaerobic