The Nitrogen Cycle

Question 0

What is nitrogen used for?

Answer 0

Making proteins for growth

Question 1

How much nitrogen is in the atmosphere?

Answer 1

78%

Question 2

Describe nitrogen cycle

Answer 2

Nitrogen in air is turned into nitrates in soil
Plants get nitrogen from soil
Animals eat plants - food chain
Decomposers break down proteins from dead plants and animals and urea to form ammonia, returning nitrogen compounds to soil

Question 3

What is nitrogen fixation?

Answer 3

Turning N2 in air to nitrogen compounds in soil by

1. Lightning - nitrogen reacts with oxygen to give nitrates
2. Nitrogen fixing bacteria in roots and soil

Question 4

What are the 4 types of bacteria in nitrogen cycle?

Answer 4

Decomposers - decompose proteins and urea into ammonia
Nitrifying bacteria - turn ammonia into nitrates
Nitrogen-fixing bacteria - turn atmospheric N2 into nitrogen
compounds plants can use
Denitrifying bacteria - turns nitrates back into N2 gas

Question 5

Where would you find nitrogen fixing bacteria?

Answer 5

Soil

Nodules on roots of some plants (peas and beans)