Question

Oxygen evolution takes place during photosynthesis in green plants but not in bacterial photosynthesis, because _________________.

• A. Bacteria are prokaryotic and green plants are eukaryotic
• B. Only photosystem I is present in bacterial photosynthesis
• C. Bacterial cell wall composition is different from green plant cell wall
• D. Rate of $O_2$ consumption in bacteria is higher than that in green plants

Answer 1

The correct option is B Only photosystem I is present in bacterial photosynthesis

There are two photosystems PS I and PS II. Photosynthetic bacteria have only PS I and absence of PSII makes them carry out cyclic photophosphorylation wherein $H_{2}S$ serves as an electron donor, rather than water, and there is no release of oxygen. The low light intensity and anaerobic conditions favor cyclic photophosphorylation.

Thus the correct answer is option A.