Nitrogen Cycle

Question 1

What do plants need to grow well?

Answer 1

Nitrates

Question 2

How would nitrogen get into animals?

Answer 2

Through the foods that they eat

Question 3

How does nitrogen leave an animal?

Answer 3

Through death or excretion

Question 4

How does nitrogen get into plants?

Answer 4

Through the air

.Absorption by plant roots

Question 5

How does nitrogen from the air get into plants?

Answer 5

By root nodule bacteria

Question 6

How does nitrogen from soil go into the air?

Answer 6

.Breakdown by soil bacteria

Question 7

How does nitrogen in the air get into the soil?

Answer 7

.By soil bacteria and lightning

Question 8

How does nitrogen from proteins and Urea get into the soil?

Answer 8

.Decomposers including soil bacteria

Question 9

What do farmers add to crop plants in order for them to grow better?

Answer 9

Fertiliser

Question 10

What does crop rotation mean?

Answer 10

.Growing different crops each year on a rotation basis

Question 11

What does crop rotation improve?

Answer 11

Soil fertility

Question 12

Give two reasons why crop rotation improves soil fertility

Answer 12

.Different crops remove different nutrients from the soil
.Plants such as clover have nitrogen fixing bacteria in their roots, and can be ploughed back into the soil to add nitrates

Question 13

Give an example of a plant that has nitrogen fixing bacteria

Answer 13

Clover

Question 14

What do different crops remove from the soil?

Answer 14

Different nutrients

Question 15

What are Nitrogen fixing bacteria?

Answer 15

.Prokaryotic microorganisms that transform nitrogen gas from the atmosphere into fixed nitrogen compounds such as ammonia that are usable by plants

Question 16

What substance does the decomposing bacteria form?

Answer 16

Ammonia

Question 17

What do denitrifying bacteria do?

Answer 17

These bacteria remove nitrogen from the cycle by breaking down nitrates back to nitrogen gas