Question

​Why oxygen is never released during synthesis of food in photoautotrophs even though they have chlorophyll, utilize sunlight and CO2 from the atmosphere like plants?

• A. Because they use different precursors to produce energy
• B. Because they do not absorb water like plant roots
• C. Because they use hydrogen sulphide instead of water as the raw material
• D. Because they do not have the necessary biological components to do so

Answer 1

The correct option is C Because they use hydrogen sulphide instead of water as the raw material

Van Niel studied bacterial photosynthesis and observed that, unlike green plants, certain bacteria such as green sulphur bacteria use hydrogen sulphide as hydrogen donor instead of water and hence oxygen is not released during photosynthesis. This is called anoxygenic photosynthesis.