The presence of ____________ would help to identify `C_(4)` plants.

Options

A. Mesophylll cells
B. Bundle sheath cells
C. Phosphoenol pyruvate
D. RuBisCO enzyme

Answer

To identify C4 plants, the presence of **bundle sheath cells** would be a key indicator. Here’s a step-by-step breakdown of the reasoning:

### Step-by-Step Solution:

1. **Understanding Plant Types**:
- Plants are categorized mainly into two types based on their photosynthetic pathways: C3 and C4 plants.
- C3 plants are adapted to normal environmental conditions, while C4 plants thrive in harsher climates, characterized by high sunlight and low water availability.

2. **Identifying Unique Features of C4 Plants**:
- C4 plants have specialized structures that help them efficiently perform photosynthesis under stress conditions.
- One of the most distinctive features of C4 plants is the presence of **bundle sheath cells**.

3. **Role of Bundle Sheath Cells**:
- Bundle sheath cells surround the vascular tissue in the leaves and are involved in the process of photosynthesis.
- They work in conjunction with mesophyll cells to convert C4 acids into C3 acids, which is a crucial step in the carbon fixation process.

4. **Comparison with C3 Plants**:
- C3 plants do not have bundle sheath cells organized in the same way as C4 plants, making this a unique identifying feature.
- Other components like mesophyll cells, phosphoenolpyruvate, and the enzyme Rubisco are present in both C3 and C4 plants, thus they cannot be used to distinguish between the two.

5. **Conclusion**:
- Therefore, the presence of **bundle sheath cells** is a definitive characteristic that helps in identifying C4 plants.

### Final Answer:
The presence of **bundle sheath cells** would help to identify C4 plants.