Life On Earth- Topic 5

Question 0

What do fertilisers contain?

Answer 0

Nutrients

Question 1

Name 3 ways to increase food yield.

Answer 1

Monocultures
GM crops
Intensive farming

Question 2

Why are fertilisers used?

Answer 2

When a crop is harvested the natural processes of the nitrogen cycle do not occur so soil nutrients are not replaced and the soil becomes less fertile

Question 3

What are pesticides used for?

Answer 3

Farmers spray pesticides on crops to kill pests which may reduce crop yield.

Question 4

What is a problem with a pesticides?

Answer 4

Can kill helpful organisms as well as harmful ones

Question 5

What is bio accumulation?

Answer 5

Many pesticides are non biodegradable chemicals that don’t break down in the environment and stay in soil

Question 6

What is the end result of bioaccumulation

Answer 6

The chemicals are passed along food chain becoming more concentrated and could kill or severely affect final consumer

Question 7

How can bioaccumulation be avoided?

Answer 7

By using biological control

Question 8

What is a problem with fertilisers (6 steps)

Answer 8

Fertilisers leach into fresh water
Water becomes rich in nutrients
Algal bloom occurs due to rapid growth of algae
Bacteria feed on dead algae and multiply rapidly
Bacteria use up dissolved oxygen in water
Fish die due to lack of oxygen

Question 9

What is an indicator species?

Answer 9

Whose presence or absence indicates the quality of environment.