Question

Which of the following is incorrect about the light reactions of photosynthesis?

• A. $P_{680}$ and $P_{700}$ are the reaction centres of PS-I and PS-II respectively
• B. Light energy provides energy for the photolysis of water through excitation of the reaction centre of PS-II
• C. NADPH is not produced in cyclic electrons transport in light reactions
• D. Reactions of the two photosystems are needed for the reduction of NADP

Answer 1

The correct option is A $P_{680}$ and $P_{700}$ are the reaction centres of PS-I and PS-II respectively

Photosystem II have absorption peak of approximately 680 nanometers and the reaction centre pigment is called P${}_{680}$ while that of PSI have absorption peak of approximately 700 nanometers and is called as P${}_{700}$. Sunlight provides energy for the splitting of water during light reaction. Z scheme of light reaction is a non-cyclic flow of electron and involves both PS I and PSII to produce NADPH while cyclic photophosphorylation does not pass electrons to NADP and NADPH is produced.

So, the correct option is A.