2022 Paper 2

Question 1

Give three harmful substances that could cause water pollution

Answer 1

Sewage
Fertiliser
Sulphur dioxide

Question 2

What could a person do to reduce chance of type 2 diabetes

Answer 2

Do more excercise
Eat a low-fat low, low carbohydrate diet

Question 3

Describe how substances that pollute the air could be harmful to humans

Answer 3

Carbon dioxide - causes global warming. Leads to polar ice caps melting so rising sea level and chance of floods leading to habitat loss.
Sulphur dioxide - damages leaves so less photosynthesis
Carbon monoxide - combines with body’s haemoglobin so less oxygen carried by blood
Carbon particulates + soot - covers leaves and blocks light so less photosynthesis so less glucose made. Also causes damage to lungs and breathing difficulties eg bronchitis
Sewage (water pollution) - bacteria multiply and use oxygen in respiration so water animals can’t respire
Fertiliser (water pollution) - algae multiply and block light do plants can’t photosynthesis leading to lack of oxygen for fish respiration

Question 4

Does correlation always mean causation

Answer 4

No

Question 5

How to improve reaction time practical

Answer 5

Use computer tests as it eliminates human error

Question 6

How does hair standing up on body keep people warm

Answer 6

Traps an insulating layer of air

Question 7

How to isolate a gene from genome

Answer 7

Use enzymes