Question

Which of the following conditions are favourable for cyclic photophosphorylation?

• A. Anaerobic condition
• B. Aerobic and optimum light
• C. Aerobic and low light intensity
• D. Anaerobic and low light intensity

Answer 1

The correct option is D Anaerobic and low light intensity

Cyclic photophosphorylation is non-oxygenic photosynthesis in which electrons are passed from P700 of PS-I, via electron transfer chain, to back to P700 with the formation of ATP. Inorganic compounds, not water, serve as energy/electron source and oxygen is not released. PSI absorbs light below 680nm while PS II is activated by light below 700 nm. The low light intensity and anaerobic conditions favour cyclic photophosphorylation while optimum or higher light intensity and aerobic conditions favour non-cyclic photophosphorylation.

So, the correct answer is option D.