Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).

Assertion (A) : Manganese deficiency in plants primarily affects the photosynthetic process.
Reason (R) : Manganese is a cofactor for several enzymes involved in the photosynthetic electron transport chain, facilitating electron transfer reactions within chloroplasts.

In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A).
• B. Both (A) and (R) are correct but (R) is NOT the correct explanation of (A).
• C. (A) is correct but (R) is not correct.
• D. (A) is not correct but (R) is correct.

Hint:

Remember that manganese (\(\text{Mn}\)) is essential for the splitting of water molecules in Photosystem II.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Manganese (\(\text{Mn}\)) is an essential micronutrient involved in key biochemical reactions, particularly within plant chloroplasts.

Step 2: Detailed Explanation:
Assertion (A) is correct because a lack of manganese severely limits a plant's ability to carry out photosynthesis, often resulting in interveinal chlorosis on younger leaves.
Reason (R) is correct because manganese plays an essential role in the Oxygen-Evolving Complex (OEC) of Photosystem II.
It serves as a cofactor that facilitates the photolysis of water (\(2\text{H}_2\text{O} \rightarrow \text{O}_2 + 4\text{H}^+ + 4\text{e}^-\)), which supplies electrons for the photosynthetic electron transport chain.
Therefore, (R) explains the biological mechanism behind (A).

Step 3: Final Answer:
Both (A) and (R) are correct, and (R) is the correct explanation of (A).