Cell membrane was first discovered by

Options

A. Schleiden
B. Schwann
C. Hooke
D. Brown

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks who first discovered the cell membrane. The options provided are Skledin, Schwann, Hoek, or Brown.

2. **Identifying Key Figures**:
- Skledin (Matthias Schleiden) was a botanist who worked on plant cells.
- Schwann (Theodor Schwann) was a zoologist who studied animal cells.
- Robert Hooke is known for discovering cells in cork.
- Robert Brown discovered the nucleus.

3. **Reviewing Contributions**:
- In 1838, Matthias Schleiden proposed that all plants are made of cells.
- In 1839, Theodor Schwann extended this idea to animals, stating that animal cells also have an outer membrane, which is known as the plasma membrane.

4. **Conclusion**: The cell membrane was first discovered by Theodor Schwann in 1839 as he compared animal and plant cells and identified the plasma membrane.

5. **Final Answer**: Therefore, the correct answer to the question is Schwann.

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