Name the cells which do not have well defined nuclear membrane.

Options

A. Prokaryotic cells
B. Eukaryotic cells
C. Symbiotic cells
D. None of the above

Explanation

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the type of cells that do not have a well-defined nuclear membrane.

2. **Identifying Cell Types**: There are two main types of cells: prokaryotic and eukaryotic.
- **Prokaryotic Cells**: These are simple cells that lack a nucleus and membrane-bound organelles.
- **Eukaryotic Cells**: These cells have a well-defined nucleus enclosed by a nuclear membrane.

3. **Analyzing Prokaryotic Cells**: Prokaryotic cells, such as bacteria, do not have a well-defined nuclear membrane. Instead, their genetic material is located in a region called the nucleoid, which is not surrounded by a membrane.

4. **Analyzing Eukaryotic Cells**: Eukaryotic cells, which include plant and animal cells, have a well-defined nuclear membrane that encloses the nucleus.

5. **Conclusion**: Based on the analysis, the cells that do not have a well-defined nuclear membrane are **prokaryotic cells**.

### Final Answer:
The cells which do not have a well-defined nuclear membrane are **prokaryotic cells**.

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