Question 1

What is the nitrogen cycle?

Accepted Answer

The cycle of processes that move nitrogen through both biotic and abiotic elements of the earth

Question 2

What is nitrogen fixation?

Accepted Answer

The process that turns nitrogen gas () into nitrate () so that plants can use it

(see how it occurs)

Question 3

What are the two ways nitrogen fixation can occur?

Accepted Answer

Biotically: nitrogen-fixing bacteria convert  into ammonia, which becomes ammonium, and is then converted into nitrate in nitrification

Abiotically:  can directly be turned into nitrate when it is exposed to lightning or industrial processes

Question 4

What is nitrification?

Accepted Answer

The process that converts ammonia and other compounds into nitrite () and then nitrate ()

Question 5

What is nitrogen assimilation?

Accepted Answer

The process that plants use to form organic nitrogen compounds from inorganic nitrogen compounds

(plants cannot use inorganic nitrogen compounds directly, so they rely on assimilation)

Question 6

What is ammonification?

Accepted Answer

The process of decomposers breaking down organic into inorganic ammonium

Question 7

What is denitrification?

Accepted Answer

The process of bacteria reducing nitrite and nitrate to gaseous forms of nitrogen so that it can return back to the atmosphere

->

Question 8

How do humans disrupt the nitrogen cycle?

Accepted Answer

By inserting excess nitrogen into ecosystems, for example, by overuse of nitrogen-based fertilizers

(can lead to algal blooms and other disruptions)

1.5 The Nitrogen Cycle, AP Environmental Science Flashcards