8.2: The Carbon Cycle

Question 1

Why is the carbon cycle important?

Answer 1

• carbon is essential for life and required in the formation of organic compounds

Question 2

What do photosynthetic organisms do in the carbon cycle?

Answer 2

• photosynthetic organisms convert CO2 to organic molecules that are used by heterotrophs

Question 3

Give some examples of carbon reservoirs on earth. (6)

Answer 3

• fossil fuels
• soils and sediments
• solutes in oceans
• plant and animal biomass
• the atmosphere
• sedimentary rocks

Question 4

What activities contribute to CO2 in the atmosphere? (2)

Answer 4

• CO2 is taken up and released through photosynthesis and respiration
• volcanoes and the burning of fossil fuels