Assertion : Photorespiration is a useful process where there is no synthesis of ATP energy.
Reason : RuBisCO is present in mesophyll cells of `C_(4)` plants, hence they show more productivity.

Options

A. If both are true with reason being correct explanation
B. both true but reason is not correct explanation
C. assertion is true but reason is wrong
D. both are wrong.

Answer

To solve the assertion and reason question, we need to analyze both statements carefully.

### Step 1: Analyze the Assertion
The assertion states: "Photorespiration is a useful process where there is no synthesis of ATP energy."
- **Analysis**: Photorespiration is a process that occurs in plants where RuBisCO (Ribulose bisphosphate carboxylase/oxygenase) fixes oxygen instead of carbon dioxide, leading to the production of a compound that is eventually converted back to RuBP (Ribulose bisphosphate). During this process, ATP is consumed rather than produced. Therefore, the assertion that photorespiration is useful is incorrect because it is generally considered a wasteful process due to the consumption of energy (ATP) without producing any useful energy.

### Step 2: Analyze the Reason
The reason states: "RuBisCO is present in mesophyll cells of C4 plants, hence they show more productivity."
- **Analysis**: In C4 plants, RuBisCO is actually located in the bundle sheath cells, not the mesophyll cells. In C4 photosynthesis, carbon dioxide is initially fixed in the mesophyll cells to form a four-carbon compound, which is then transported to the bundle sheath cells where RuBisCO operates primarily as a carboxylase. This arrangement minimizes photorespiration, thus increasing productivity. Therefore, the reason given is also incorrect.

### Step 3: Conclusion
Both the assertion and the reason are incorrect. Therefore, the correct answer to the question is that both statements are false.

### Final Answer:
Both the assertion and reason are incorrect.

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