Question

Which of the following is not true about photosynthesis?

• A. In non-cyclic photophosphorylation, water is split and oxygen is released
• B. Photosystem-II makes noncyclic photophosphorylation more efficient than does cyclic photophosphorylation.
• C. Cyclic system is used when there is insufficient $NAD{P}^{+}$ present to absorb electrons in plant cells
• D. More carbohydrate is produced during cyclic photophosphorylation than during non-cyclic photophosphorylation

Answer 1

Answer: (D)

More carbohydrate is produced during cyclic photophosphorylation than during non-cyclic photophosphorylation

Cyclic Photo-phosphorylation happens with the help of photosynthesis, a process of producing carbohydrates by green plants using carbon dioxide and water in the presence of sunlight. Cyclic photo-phosphorylation exists to provide energy for the Calvin cycle and involves the only p680 in photo-system ll and its product is ATP. Non-cyclic photo-phosphorylation is carried out using p700 in photo-system l and p680 in photo-system ll and it produces NADPH and ATP. There is no production of carbohydrate in the photosystems and hence cyclic or non-cyclic does not play a role.

So, the correct option is, 'More carbohydrate is produced during cyclic photophosphorylation than during non-cyclic photophosphorylation'.