Question

Find the incorrect statement(s) about photosynthesis from the following:
A. The water splitting complex is associated with PS I.
B. $C_4$ plants use the $C_3$ pathway of $CO_2$ fixation as the main biosynthetic pathway.
C. In $C_4$ plants, photorespiration does not occur.
D. $C_3$ plants exhibit 'Kranz' anatomy.
E. ATP synthesis in chloroplast occurs through chemiosmosis. Choose the answer from the options given below:

• A. B and C only
• B. B only
• C. A and D only
• D. B and E only

Hint:

PS \textbf{II} is for \textbf{II}ydrogen (splitting water into $H^+$ and $O_2$). Kranz = $C_4$ (Wreath-like cells).

Answer 1

The Correct Option is C

Let's analyze each statement to find the inaccuracies:
• Statement A is Incorrect: The water-splitting complex (Oxygen Evolving Complex) is associated with Photosystem II (PS II), not PS I. It is located on the inner side of the thylakoid membrane.
• Statement D is Incorrect: $C_4$ plants exhibit Kranz anatomy, which is characterized by bundle sheath cells arranged in a wreath-like manner. $C_3$ plants do not have this structure.
• Statement B is Correct: Even in $C_4$ plants, the actual synthesis of sugars occurs via the $C_3$ cycle (Calvin Cycle) in the bundle sheath cells.
• Statement C is Correct: $C_4$ plants have a mechanism to increase $CO_2$ concentration around RuBisCO, thereby minimizing photorespiration.
• Statement E is Correct: Both mitochondria and chloroplasts use the chemiosmotic gradient to synthesize ATP.