Question

In the light reactions of photosynthesis,

• A. PS I produces strong oxidant while PS II a strong reductant.
• B. PS I produces strong reductant $NADPH$ while PS II a strong oxidant.
• C. PS I emits electrons for PS II.
• D. PS I produces ATP which is not formed by PS II.

Answer 1

The correct option is B PS I produces strong reductant $NADPH$ while PS II a strong oxidant.

PS I: This system produces a strong reductant which reduces ${NADP}^{+}$ to $NADPH$.

This system does not directly involve with the photooxidation of water and evolution of molecular oxygen.

PS II: This system is directly involved with the photooxidation of water and evolution of molecular oxygen.

It donates electrons to PS I when ${NADP}^{+}$ is reduced.

Hence, the correct answer is 'PS I produces strong reductant $NADPH$ while PS II a strong oxidant'.