Question

Cyclic variations of CO₂ concentration in the atmosphere are due to changes in ______.

Options

• photosynthetic activity

• respiratory activity

• burning of fossil fuels

• action of infra-red rays

Answer 1

Cyclic variations of CO₂ concentration in the atmosphere are due to changes in photosynthetic activity.

Explanation:

Cyclic variations of CO₂ concentration in the atmosphere occur due to changes in photosynthetic activity. During periods when plants and aquatic vegetation engage in high photosynthesis, they absorb more CO₂ from the atmosphere, lowering its concentration. Conversely, when photosynthesis decreases, CO₂ concentration rises due to respiration and decomposition processes. This seasonal cycle causes the observed cyclic variations in atmospheric CO₂ levels.