Statement a. Photorespiration decreases photosynthetic output.
Statement b. In photorespiratory pathway, neither ATP no NADPH is produced

Options

A. Both the statements a and b are correct
B. Both the statements a and b are wrong
C. Statement a is correct and statement b is wrong
D. Statement b is correct and statement a is wrong.

Answer

To analyze the statements given in the question, we will break down each statement step by step.

### Step 1: Understanding Photorespiration
- **Definition**: Photorespiration is a process that occurs in plants where the enzyme RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase) can catalyze the reaction of ribulose bisphosphate (RuBP) with oxygen instead of carbon dioxide.
- **Outcome**: This leads to the formation of phosphoglycolate and phosphoglycerate, which are not useful for the plant in terms of energy production.

**Hint**: Remember that RuBisCO can act as both a carboxylase and an oxygenase depending on the concentrations of CO2 and O2.

### Step 2: Analyzing Statement A
- **Statement A**: "Photorespiration decreases photosynthetic output."
- **Explanation**: When RuBisCO uses oxygen instead of carbon dioxide, it results in a lower production of glucose and other carbohydrates, which are the primary products of photosynthesis. This means that photorespiration indeed decreases the overall photosynthetic output.

**Hint**: Consider how the efficiency of photosynthesis is affected when RuBisCO reacts with oxygen instead of carbon dioxide.

### Step 3: Analyzing Statement B
- **Statement B**: "In the photorespiratory pathway, neither ATP nor NADPH is produced."
- **Explanation**: During photorespiration, the process does not generate ATP or NADPH, which are crucial for the energy and reducing power needed for the Calvin cycle. Instead, photorespiration consumes ATP that is already present in the plant.

**Hint**: Reflect on the energy requirements of the Calvin cycle and how photorespiration impacts those requirements.

### Conclusion
Both statements A and B are correct:
- **Statement A** is correct because photorespiration does decrease the photosynthetic output.
- **Statement B** is correct because the photorespiratory pathway does not produce ATP or NADPH.

### Final Answer
Both statements A and B are correct.