Question

In which of the following organism oxygen does not evolve during photosynthesis?

• A. Photosynthetic red algae
• B. Photosynthetic green algae
• C. Photosynthetic blue-green algae
• D. Photosynthetic bacteria

Answer 1

The correct option is D Photosynthetic bacteria

• Algae (red, green, brown), blue-green algae and higher plants carry on oxygenic photosynthesis, in which water serves as the source of an electron. Water splits to supply electrons and oxygen is released as a by-product.
• In photosynthetic sulphur bacteria, water is not used. Hydrogen sulphide or other reduced sulphur compounds are used as a source of electrons.
• Consequently, oxygen is not released but sulphur is deposited in their cells.
  Hence, the correct option is D.