Question

Which of the following contribute to the water vapour content in the atmosphere?

• A. Respiration.
• B. Transpiration.
• C. Combustion.
• D. Photosynthesis.

Answer 1

Answer: (A), (B), (C)

The correct options are
A

Respiration.

B

Transpiration.

C

Combustion.

Respiration, Combustion, and Transpiration- all produce water vapour as a by-product.

Combustion: Fuel + Oxygen $\to$ Carbon dioxide + Water vapour + Heat

Respiration: Sugar + Oxygen $\to$ Carbon dioxide + Water vapour

But water vapour is not produced during photosynthesis.

Photosynthesis: Carbon dioxide + Water $\to$ Sugar + Oxygen