Which statement about photosynthesis are correct
(a) First `CO_(2)` acceptor in `C_(4)` cycle is PGA
(b) In `C_(3)` plants, first stable product of photosynthesis is RuBP
(c) Cyclic photophosphorylation results in formation of ATP
(d) Oxygen liberated during photosynthesis comes from water

Options

A. a and b alone are correct
B. a and c alone are correct
C. c and d alone are correct
D. b and c alone are correct

Answer

To determine which statements about photosynthesis are correct, let's analyze each statement step by step.

### Step 1: Analyze Statement (a)
**Statement (a):** First CO₂ acceptor in C₄ cycle is PGA.

- **Explanation:** In the C₄ cycle, the first carbon dioxide acceptor is phosphoenolpyruvate (PEP), not phosphoglyceric acid (PGA). PGA is actually produced later in the cycle as a result of the fixation of CO₂.
- **Conclusion:** This statement is **incorrect**.

### Step 2: Analyze Statement (b)
**Statement (b):** In C₃ plants, the first stable product of photosynthesis is RuBP.

- **Explanation:** In C₃ plants, the first stable product of the Calvin cycle (C₃ cycle) is actually phosphoglyceric acid (PGA), not ribulose bisphosphate (RuBP). RuBP is the molecule that reacts with CO₂, but it is not the first stable product.
- **Conclusion:** This statement is **incorrect**.

### Step 3: Analyze Statement (c)
**Statement (c):** Cyclic photophosphorylation results in the formation of ATP.

- **Explanation:** Cyclic photophosphorylation is a process that occurs during the light reactions of photosynthesis, where ATP is generated through the flow of electrons in a cyclic manner. This process does indeed result in the formation of ATP.
- **Conclusion:** This statement is **correct**.

### Step 4: Analyze Statement (d)
**Statement (d):** Oxygen liberated during photosynthesis comes from water.

- **Explanation:** During the light reactions of photosynthesis, water molecules are split (a process called photolysis) to release oxygen. Therefore, the oxygen that is liberated during photosynthesis does indeed come from water.
- **Conclusion:** This statement is **correct**.

### Final Conclusion
- **Correct Statements:** (c) and (d) are correct.
- **Incorrect Statements:** (a) and (b) are incorrect.

### Summary of Answers:
- (a) Incorrect
- (b) Incorrect
- (c) Correct
- (d) Correct