Cell theory was proposed by
(a) Schleiden and Schwann
(b) Watson and Crick
(c) Darwin and Wallace
(d) Mendel and Morgan

Options

A. Schleiden and Schwann
B. Watson and Crick
C. Darwin and Wallace
D. Mendel and Morgan

Answer

To answer the question regarding who proposed the cell theory, we can follow these steps:

1. **Understand the Question**: The question asks who proposed the cell theory. We have four options to choose from.

2. **Recall the Cell Theory**: The cell theory states that:
- All living organisms are made up of cells.
- The cell is the basic structural and functional unit of life.
- New cells are formed from pre-existing cells.

3. **Identify the Scientists**: Now, let's look at the options provided:
- (a) Schleiden and Schwann
- (b) Watson and Crick
- (c) Darwin and Wallace
- (d) Mendel and Morgan

4. **Match Scientists with Contributions**:
- **Schleiden and Schwann**: These two scientists are known for formulating the cell theory in the mid-19th century. Schleiden studied plant cells, and Schwann studied animal cells.
- **Watson and Crick**: They are famous for discovering the structure of DNA, not for cell theory.
- **Darwin and Wallace**: They are known for the theory of evolution by natural selection.
- **Mendel and Morgan**: They are known for their work in genetics.

5. **Select the Correct Option**: Based on the information, the correct answer is (a) Schleiden and Schwann, as they proposed the cell theory.

6. **Conclusion**: Therefore, the answer to the question is (a) Schleiden and Schwann.