In sunflower stem, the pericycle is present in the from of patches and they are formed by

Options

A. Parenchmatous cell
B. Sclerenchymatous cells
C. Collenchymatous cells
D. Both (a) and (b)

Answer

To solve the question regarding the presence of pericycle in sunflower stems, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Sunflower Stem**:
- Sunflower is a dicot plant, which means it has a specific arrangement of tissues in its stem.

2. **Identify the Layers in the Stem**:
- The stem consists of several layers:
- **Epidermis** (outermost layer)
- **Cortex** (beneath the epidermis)
- **Pericycle** (located just inside the endodermis)

3. **Function of the Pericycle**:
- The pericycle plays a crucial role in the formation of vascular cambium and cork cambium. It is involved in secondary growth.

4. **Composition of the Pericycle**:
- The pericycle is primarily composed of specific types of cells. The options given are:
- A) Parenchyma cells
- B) Sclerenchyma cells
- C) Collenchyma cells
- D) Both A and B

5. **Evaluate the Options**:
- **Parenchyma Cells**: These are generally found in the cortex but not primarily in the pericycle.
- **Sclerenchyma Cells**: These cells provide strength and support and are indeed found in the pericycle.
- **Collenchyma Cells**: These are typically found in the cortex and provide flexibility, not in the pericycle.
- **Both A and B**: Since parenchyma is not a component of the pericycle, this option is incorrect.

6. **Conclusion**:
- Based on the analysis, the correct answer is **B) Sclerenchyma cells**, as the pericycle in sunflower stems is primarily formed by sclerenchyma cells.

### Final Answer:
**The pericycle in sunflower stems is formed by sclerenchyma cells (Option B).**