Ch.7.5

Question 1

Describe how plants and animals recycle carbon dioxide in the atmosphere.

Answer 1

Plants take in carbon dioxide from the air for photosynthesis.
Carbon dioxide is produced during respiration in plants and animals and is given out into the air.
Plants then take in carbon dioxide again.

Question 2

Through the processes of ___________________ and _____________________—two _________________________________________— ________________________ and ________________ in the atmosphere is recycled.

Answer 2

photosynthesis, respiration, essential life processes, carbon dioxide, oxygen

Question 3

Why is there a balance of carbon dioxide and oxygen in nature? Why is this important?

Answer 3

This is because of the processes of photosynthesis and respiration.
It is important for the survival of living things.

Question 4

What are disrupting the balance of carbon dioxide and oxygen in Nature nowadays?

Answer 4

Many human activities.

Question 5

Name five examples of human activities that impact the balance of carbon dioxide and oxygen in Nature. Describe how do they impact this balance.

Answer 5

Burning fossil fuels—to generate electricity, for transport, for industrial activities
Cutting down trees
Population increases
They cause an increase in the amount of carbon dioxide in the atmosphere

Question 6

Why are trees cut down?

Answer 6

For timber and to provide land.

Question 7

What is the impact of cutting down trees?

Answer 7

The amount of carbon dioxide absorbed by plants for photosynthesis decreases, leading to a larger amount of CO2.

Question 8

What is the impact of burning fossil fuels?

Answer 8

CO2 is generated in this process.

Question 9

Why have people burnt fossil fuels for the past 50 years? What has this caused?

Answer 9

To meet the demand of energy; this has caused the amount of carbon dioxide in the atmosphere to increase rapidly.

Question 10

How does the increasing amount of carbon dioxide in the atmosphere affect the environment? Why?

Answer 10

This enhances the greenhouse effect and leads to global warming. This is because carbon dioxide is one of the greenhouse gases.

Question 11

What is the greenhouse effect?

Answer 11

The effect of how some gases in the Earth’s atmosphere can trap heat from the sun and keep the Earth warm.

Question 12

What are the gases that can trap heat from the Sun called?

Answer 12

greenhouse gases.

Question 13

Name five common greenhouse gases.

Answer 13

Carbon dioxide (CO2)
Dinitrogen oxide (N2O)
Methane (CH4)
Trichlorofluoromethane (CFCs)
Ozone (O3)

Question 14

What happens when the greenhouse effect is enhanced? What is the effect called?

Answer 14

More heat is trapped in the atmosphere and the average temperature of the Earth increases. Global warming.

Question 15

What are the possible harmful effects of global warming on the environment?

Answer 15

—The melting of ice at polar regions

—Climate change

Question 16

Describe the impact of the melting of ice at polar regions.

Answer 16

Average sea levels rise, causing flooding in low-lying coastal areas.
Living things in polar regions such as polar bears may lose their habitat.

Question 17

Describe the impact of climate change.

Answer 17

More frequent heat waves, storms and droughts.

Food shortages as weather becomes less favourable for growing crops and affects crop growth.

Question 18

What is the purpose of promoting low-carbon living?

Answer 18

To slow down global warming and prevent climate change from getting worse.

Question 19

What does low-carbon living refer to?

Answer 19

A lifestyle that emits less carbon dioxide.

Question 20

What can we do to help slow down global warming?

Answer 20

We can reduce the emission of greenhouse gases in daily life.

Question 21

name three solutions of global warming.

Answer 21

• afforestation
• use public transport
• using renewable energy eg solar