Which one of the following is found in cells of plant, animal as well as bacteria?

Options

A. chloroplast
B. cell membrane
C. nucleus
D. cell wall

Explanation

To solve the question "Which one of the following is found in cells of plant, animal as well as bacteria?", we will analyze the provided options step by step.

### Step 1: Understand the Options
The options given are:
1. Chloroplast
2. Cell membrane
3. Nucleus
4. Cell wall

### Step 2: Analyze Each Option
- **Chloroplast**: This organelle is responsible for photosynthesis and is found in plant cells and some bacteria, but it is absent in animal cells. Therefore, this option is incorrect.

- **Cell Membrane**: Also known as the plasma membrane, this structure is present in all types of cells, including plant cells, animal cells, and bacterial cells. This option is likely correct.

- **Nucleus**: The nucleus is present in plant and animal cells, but bacteria do not have a true nucleus (they have a nucleoid instead). Thus, this option is incorrect.

- **Cell Wall**: The cell wall is found in plant cells and bacterial cells, but it is absent in animal cells. Therefore, this option is also incorrect.

### Step 3: Conclusion
After analyzing all the options, the only structure that is found in plant cells, animal cells, and bacterial cells is the **cell membrane**.

Thus, the correct answer is **Cell Membrane**.

### Final Answer
**Cell Membrane**

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