Which process is responsible for oxygen production in aquatic plants?

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

Answer: (C)

Oxygen production in aquatic plants comes from photosynthesis. In the presence of light, chloroplasts use light energy to drive the transformation of carbon dioxide and water into sugars. A crucial step is the splitting of water molecules during the light reactions, which releases oxygen gas. This oxygen then diffuses into the surrounding water, contributing to the dissolved oxygen that aquatic ecosystems rely on.

Respiration, on the other hand, uses oxygen to release energy from sugars, so it consumes O2 rather than producing it. Fermentation occurs when oxygen is scarce and does not generate significant amounts of oxygen. Transpiration is simply the loss of water through the plant and doesn’t produce oxygen either.

So the oxygen you observe from aquatic plants comes from photosynthesis, specifically the water-splitting process in the light reactions.