Question

Given below are two statements:
Statement I : Light reaction takes place in grana
Statement II : Dark reaction takes place in stroma
In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is correct but Statement II is false
• D. Statement I is incorrect but Statement II is true

Hint:

Light reactions = Grana (thylakoids); Dark reactions (Calvin cycle) = Stroma (chloroplast matrix).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Photosynthetic reactions are strictly compartmentalized between membranous thylakoids and the aqueous chloroplast stroma.

Step 2: Detailed Explanation:
1. Statement I is TRUE: Light-dependent reactions (photolysis of water, electron transport through PS-II and PS-I, and photophosphorylation yielding ATP and NADPH) occur within the thylakoid membranes organized into grana.
2. Statement II is TRUE: Light-independent dark reactions (the Calvin-Benson cycle of enzymatic $\text{CO}_2$ fixation and reduction to triose phosphates by RuBisCO) take place in the aqueous soluble matrix of the stroma.

Step 3: Final Answer:
Therefore, both Statement I and Statement II are true.