Topic 7 - Ecology

Question 1

What is water pollution?

Answer 1

Discharge of harmful substances into bodies of water

Question 2

Sources of pollution (3)

Answer 2

Combustion of fossil fuels
Food being grown
Land used for industrial/housing

Question 3

Sources of water pollution (4)

Answer 3

(Nitrate) fertilisers washed into water-hard to remove (soluble)
Pesticides washed/blown into water
Sulfur dioxide in the air dissolves in water
Human sewage-microorganisms use oxygen to decompose it which reduces levels of oxygen in water

Question 4

Sewage treatment

Answer 4

surplus amounts of oxygen

microorganisms completely break down waste before it is discharged in water

Question 5

What can different species tell you about the water

Answer 5

how polluted it is as some are more tolerable than others

Question 6

What problems can occur if nutrients from fertilisers are washed into water

Answer 6

Algae flourishes - covers surface of water

prevents sunlight reaching plants - less oxygen