Multiple choice

During photosynthesis in plants the gas evolve is

  1. Carbon dioxide

  2. Nitrogen

  3. Oxygen

  4. Hydrogen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

During photosynthesis, plants release oxygen as a byproduct of the light-dependent reactions. When chlorophyll absorbs light energy, water molecules are split (photolysis) in the thylakoid membranes, releasing oxygen as a waste product. This oxygen comes from water, not from carbon dioxide, which is used in the subsequent Calvin cycle to produce glucose.

Keep practicing — related questions