`C_(4)` plants are more efficient in photosynthesis than `C_(3)` plants due to

Options

A. Presence of thin cuticle
B. Lower rate of photorespiration
C. Hgher leaf area
D. Presence of larger number of chloroplasts in the leaf cells

Answer

### Step-by-Step Solution:

1. **Understanding C3 and C4 Plants**:
- C3 plants utilize the Calvin cycle for photosynthesis, where carbon dioxide is fixed directly into a 3-carbon compound (3-PGA).
- C4 plants have a modified pathway that initially fixes carbon dioxide into a 4-carbon compound (oxaloacetate) before entering the Calvin cycle.

2. **Photosynthetic Efficiency**:
- The photosynthetic rate of C3 plants ranges from 15 to 35 mg/dm³, while C4 plants can achieve rates of 40 to 80 mg/dm³.
- This indicates that C4 plants have a higher photosynthetic efficiency compared to C3 plants.

3. **Role of Photorespiration**:
- Photorespiration is a process that occurs in C3 plants when oxygen competes with carbon dioxide for the enzyme ribulose bisphosphate carboxylase/oxygenase (RuBisCO).
- This process reduces the overall efficiency of photosynthesis because it leads to the production of glycolate instead of glucose.

4. **C4 Plants and Photorespiration**:
- C4 plants have a mechanism that minimizes photorespiration. They separate the initial carbon fixation and the Calvin cycle spatially, which reduces the oxygen concentration around RuBisCO.
- As a result, C4 plants experience negligible or absent photorespiration, allowing them to maintain a higher rate of photosynthesis.

5. **Conclusion**:
- The higher efficiency of C4 plants in photosynthesis compared to C3 plants is primarily due to the lower rate of photorespiration in C4 plants.

### Final Answer:
C4 plants are more efficient in photosynthesis than C3 plants due to the lower rate of photorespiration.

---