Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The biosynthetic phase of photosynthesis does not directly depend on the presence of light, but it cannot continue for long in the dark. Reason (R): The biosynthetic phase strictly requires ATP and NADPH, which are products of the light-dependent photochemical phase. In the light of the above state

Step-by-step solution

The biosynthetic phase (dark reaction) of photosynthesis is not directly light-driven but is entirely dependent on the products of the light reaction (ATP and NADPH) to reduce CO ₂ into sugars. When light is turned off, the supply of ATP and NADPH halts. The biosynthetic phase can continue only as long as the previously synthesized ATP and NADPH last, after which it stops. Therefore, both Assertion and Reason are correct, and the Reason correctly explains why the Assertion is true. Answer: Both Assertion and Reason