Question

Assertion (A): The primary pigment involved in photosynthesis is chlorophyll a.

Reason (R): Chlorophyll a absorbs light most effectively in the red and blue regions of the electromagnetic spectrum.

Options

• 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 and R is the correct explanation of A.

Explanation:

The assertion is true because chlorophyll a is the essential primary pigment directly responsible for converting light energy into chemical energy during photosynthesis. The reason is also true and provides the correct explanation because a pigment’s efficiency is determined by its absorption spectrum. Since chlorophyll a absorbs light most effectively in the high-energy blue and red regions of the spectrum, it successfully drives the main photochemical reactions, confirming its status as the primary pigment.