I. Sclerenchymatous cells
II. Much elongated, unbranched and tapering ends
!!I. Needle like shape
IV. Cell wall thick
V. Dead cells
VI. Found in secondary phloem
Which of the following cells is defined by the above characters?

Options

A. Sieve tube
B. Phloem parenchyma
C. Phloem fibre/bast fibre
D. Companion or albuminous cell

Answer

To identify the type of cells defined by the given characteristics, we can analyze each point step by step:

### Step-by-Step Solution:

1. **Identify the Characteristics**:
- The cells are described as **sclerenchymatous**.
- They are **much elongated**, **unbranched**, and have **tapering ends**.
- They have a **needle-like shape**.
- The **cell wall is thick**.
- The cells are **dead**.
- They are **found in secondary phloem**.

2. **Understanding Sclerenchyma**:
- Sclerenchyma is a type of plant tissue that provides structural support. It consists of dead cells with thickened walls.

3. **Analyzing Each Characteristic**:
- **Much Elongated**: This suggests that the cells are not short or rounded.
- **Unbranched and Tapering Ends**: This indicates a specific shape, which is characteristic of certain types of fibers.
- **Needle-like Shape**: This further confirms the elongated and tapered nature of the cells.
- **Thick Cell Wall**: Sclerenchyma cells typically have very thick walls, which contribute to their strength.
- **Dead Cells**: Sclerenchyma cells are known to be dead at maturity, which is a key feature.
- **Found in Secondary Phloem**: This indicates the location of these cells within the plant structure.

4. **Comparing with Other Cell Types**:
- **Collenchyma**: This type of tissue is living and has irregularly thickened walls, which does not match the characteristics.
- **Parenchyma**: These cells are living and do not have the thick walls or needle-like shape described.
- **Fibers**: Specifically, **phloem fibers** (also known as sclerenchyma fibers) fit all the characteristics mentioned.

5. **Conclusion**:
- Based on the analysis, the cells described by the characteristics are **phloem fibers**. They are elongated, unbranched, have tapering ends, a needle-like shape, thick cell walls, and are dead, found in secondary phloem.

### Final Answer:
The cells defined by the above characters are **phloem fibers**.