At maturity which of the following is enucleate ?

Options

A. Sieve cell
B. Companion cell
C. Palisade cell
D. Cortical cell

Answer

To determine which of the following cells is enucleate at maturity, we will analyze each option provided: sieve cell, companion cell, palisade cell, and cortical cell.

### Step-by-Step Solution:

1. **Understanding Enucleation**:
- Enucleation refers to the process where a cell loses its nucleus. An enucleate cell is one that does not have a nucleus at maturity.

2. **Analyzing the Options**:
- **Sieve Cell**:
- Sieve cells are part of the phloem tissue in plants. At maturity, sieve cells lose their nucleus to allow for more space to transport sugars and other molecules. Thus, they are enucleate.

- **Companion Cell**:
- Companion cells are also found in the phloem and are closely associated with sieve elements. They retain their nucleus and help in the functioning of sieve cells by providing necessary proteins and energy. Therefore, companion cells are not enucleate.

- **Palisade Cell**:
- Palisade cells are specialized cells in the leaves that are involved in photosynthesis. They contain a nucleus throughout their life and are not enucleate.

- **Cortical Cell**:
- Cortical cells are found in the cortex of stems and roots. They are generally unspecialized and also retain their nucleus at maturity. Hence, they are not enucleate.

3. **Conclusion**:
- Among the options provided, the **sieve cell** is the only cell that is enucleate at maturity.

### Final Answer:
The correct answer is **sieve cell**.

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