Question

How do humans cycle carbon from the biosphere to the atmosphere?(1 point)
Responses

by driving cars that use gasoline for fuel
by driving cars that use gasoline for fuel

by respiration
by respiration

by eating plants
by eating plants

by planting vegetable crops

Answer 1

Humans cycle carbon from the biosphere to the atmosphere primarily by **driving cars that use gasoline for fuel** and **by respiration**.

- When humans drive cars that burn fossil fuels, carbon that was stored in the earth's biosphere is released into the atmosphere as carbon dioxide (CO2).
- In respiration, humans consume oxygen and organic materials (which contain carbon) and exhale carbon dioxide back into the atmosphere.

While eating plants and planting vegetable crops do involve carbon, they are part of carbon uptake and sequestration rather than directly cycling it into the atmosphere. Thus, the most appropriate responses are driving cars that use gasoline for fuel and by respiration.