The Carbon Cycle

Carbon is essential for life, forming the basis of organic molecules. It cycles through the atmosphere, oceans, and living organisms in a process called the carbon cycle. Plants absorb atmospheric carbon dioxide for photosynthesis, which is then passed through the food chain and released back into the atmosphere via respiration. Decomposition of dead organisms can lead to fossil fuel formation, which releases carbon when burned. Oceans also play a role in carbon cycling, absorbing and releasing carbon dioxide. Human activities, such as burning fossil fuels and deforestation, disrupt this cycle, impacting the planet's balance.

What is the primary form of carbon found in the atmosphere?

• Carbon monoxide

• Ozone

• Carbon dioxide

• Methane

Which process allows plants to convert carbon dioxide into energy?

• Respiration

• Photosynthesis

• Fossilization

• Decomposition

How is carbon returned to the atmosphere when plants and animals die?

• Through photosynthesis

• By decomposition

• Through evaporation

• Via fossilization

What happens to carbon dioxide when it dissolves in cold ocean waters?

• It turns into methane

• It is released back into the atmosphere when surface waters evaporate

• It remains dissolved indefinitely

• It forms solid carbonates

What human activities are disrupting the balance of the carbon cycle?

• Burning fossil fuels and deforestation

• Enhanced decomposition

• Ocean acidification

• Increased photosynthesis