The Carbon Cycle in Earth's Atmosphere

What is the role of cellular respiration in the carbon cycle?

• It absorbs CO₂ from the atmosphere

• It releases energy from organic compounds and returns CO₂ to the atmosphere

• It breaks down dead organisms

• It forms sedimentary rocks

Which organisms are primarily responsible for breaking down dead matter and recycling carbon into the soil?

• Herbivores

• Decomposers

• Producers

• Fossil fuels

What is a carbon sink?

• A process that releases carbon into the atmosphere

• Any reservoir that absorbs more carbon dioxide from the atmosphere than it releases

• A type of fossil fuel

• A form of sedimentary rock

What is the process called when carbon is stored in sediments on the ocean floor?

• Lithification

• Decomposition

• Burial

• Combustion

What is the main way fossil fuels contribute to the carbon cycle today?

• By forming new sedimentary rocks

• By being used in photosynthesis

• By being burned and releasing CO₂ into the atmosphere

• By decomposing in the soil

Explain how the balance between photosynthesis and cellular respiration helps maintain the equilibrium of carbon in the atmosphere.

• Both processes release CO₂ into the atmosphere

• Photosynthesis absorbs CO₂ while cellular respiration releases it, balancing atmospheric CO₂ levels

• Both processes absorb CO₂ from the atmosphere

• Cellular respiration absorbs CO₂ while photosynthesis releases it

Why is the process of burial important for the long-term regulation of atmospheric CO₂ levels?

• It releases CO₂ into the atmosphere quickly

• It sequesters carbon in sediments, preventing its immediate return to the atmosphere

• It increases the rate of photosynthesis

• It forms new fossil fuels instantly

Which process in the carbon cycle converts carbon dioxide into organic matter?

• cellular respiration

• decomposition

• photosynthesis

What is the main source of carbon for plants during photosynthesis?

• carbon dioxide in the atmosphere

• carbon dioxide dissolved in water

• carbon in the soil

How do sedimentary rocks contribute to the carbon cycle?

• by absorbing carbon dioxide from the atmosphere

• by storing carbon over long periods of time

• by converting carbon into organic matter