Question

When a plant photosynthesizes, the carbon used by the plant to construct organic molecules comes from ________.

a. COâ in the atmosphere
b. COâ in the soil
c. Organic carbon in the soil
d. Single carbon atoms in the atmosphere
e. Any of these sources

Answer 1

Answer: CO2 in the atmosphere

Explanation:

During photosynthesis, plants removes carbon dioxide in large amount from the atmosphere and then utilize the carbon atoms to build up organic molecules.

Thus, this removal of CO2 from the atmosphere provide a natural solution to prevent the gas accumulation in the atmosphere, which is often generated by human activities and natural causes.