The carbon cycle

Question 1

How does carbon enter the atmosphere?

Answer 1

as carbon dioxide through respiration and combustion

Question 2

How is carbon absorbed?

Answer 2

by plants through photosynthesis (the carbon forms part of their structure)

Question 3

Animals and plants:

Answer 3

• animals feed on plants (the carbon moves through the food chain)
• most of the carbon forms parts of the animal but some is exhaled (respired)
• these plants and animals eventually die

Question 4

Decomposition:

Answer 4

• the dead plants and animals decompose into the ground
• the carbon that was in their bodies is then returned to the atmosphere as carbon dioxide
• sometimes the decomposed plants and animals turn into fossil fuels (this takes millions of years)