Nitrogen is Also Recycled in the Nitrogen Cycle

Question 1

How much nitrogen gas does the atmosphere contain?

Answer 1

About 78% nitrogen

Question 2

What is nitrogen needed for?

Answer 2

Making proteins for growth, so living organsi,s have to get it somehow

Question 3

Where do plants get their nitrogen from?

Answer 3

The soil

Question 4

What does nitrogen in the air need to be turned into before plants can use it?

Answer 4

Nitrogen compounds

Question 5

What can animals only get proteins from?

Answer 5

By eating plants (or each other)

Question 6

What is nitrogen fixation?

Answer 6

Process of turning N2 from the air into nitrogen compounds in the soil which plants can use

Question 7

Lightning -

Answer 7

There’s enough energy in a bolt of lightning to make nitrogen react with oxygen in the air to give nitrates

Question 8

Nitrogen-fixing bacteria -

Answer 8

In roots and soil

Question 9

What are the 4 types of bacteria involved in the nitrogen cycle?

Answer 9

Decomposers
Nitrifying bacteria
Nitrogen-fixing bacteria
Denitrifying bacteria

Question 10

Decomposers -

Answer 10

Break down proteins and urea and turn them into ammonia

Question 11

Nitrifying bacteria -

Answer 11

Turn ammonia in decaying matter into nitrates

Question 12

Nitrogen-fixing bacteria -

Answer 12

Turn atmospheric N2 into nitrogen compounds that plants can use

Question 13

Denitrifying bacteria -

Answer 13

Turn nitrates back into N2 gas. This is of no benefit to living organisms

Question 14

Where do some of these bacteria live?

Answer 14

Some live in the soil

Some live in nodules on plant roots

Question 15

Look at diagram page 70

Answer 15

Ok