What does the carbon cycle describe?

What does the carbon cycle describe?

• A. The movement of water through organisms.
• B. The cycle of oxygen in the atmosphere.
• C. The production of energy in cells.
• D. The recycling of carbon between living and nonliving parts of the biosphere.

Answer: (D)

The carbon cycle tracks how carbon atoms move and get reused among living organisms and the nonliving parts of the environment. Plants take carbon from the air through photosynthesis to build sugars, and animals obtain carbon by eating plants or other animals. When organisms respire, die, or decompose, carbon is released back into the air, soil, or water as carbon dioxide or organic matter. The oceans exchange carbon with the atmosphere and store carbon for long periods, and over geologic timescales carbon is locked away in rocks and fossil fuels. This describes the continual recycling of carbon between living things and their surroundings, not just the processes that move water, or the oxygen cycle, or the way cells produce energy.

The carbon cycle tracks how carbon atoms move and get reused among living organisms and the nonliving parts of the environment. Plants take carbon from the air through photosynthesis to build sugars, and animals obtain carbon by eating plants or other animals. When organisms respire, die, or decompose, carbon is released back into the air, soil, or water as carbon dioxide or organic matter. The oceans exchange carbon with the atmosphere and store carbon for long periods, and over geologic timescales carbon is locked away in rocks and fossil fuels. This describes the continual recycling of carbon between living things and their surroundings, not just the processes that move water, or the oxygen cycle, or the way cells produce energy.