Question

Assertion (A): Photosystem II comes before Photosystem I in the light-dependent reactions.

Reason (R): Photosystem II absorbs light at a shorter wavelength than Photosystem I.

पर्याय

• Both A and R are true and R is the correct explanation of A.

• Both A and R are true but R is not the correct explanation of A.

• A is true but R is false.

• A is false but R is true.

Answer 1

Both A and R are true but R is not the correct explanation of A.

Explanation:

The assertion is true because electrons travel sequentially from Photosystem II (PSII) to Photosystem I (PSI) during non-cyclic photophosphorylation. The reason is also true because PSII has a reaction center that absorbs light at a shorter wavelength of 680 nm, whereas PSI absorbs at 700 nm. However, the reason does not explain the assertion, as PSII comes first in the pathway simply because it was discovered second historically, not because of its light absorption properties.