Each cell leads a double life was first proposed by

Options

A. Schleiden
B. Grew
C. Von Mohl
D. Malpighi

Answer

To solve the question "Each cell leads a double life was first proposed by," we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Key Phrase**: The phrase "each cell leads a double life" is crucial to the question. This phrase refers to the concept that a cell functions both as an individual unit and as part of a larger organism.

2. **Recall Relevant Scientists**: The question provides four options: A. Slythin, B. Grew, C. Von Maul, and D. Malfighi. We need to recall what each of these scientists contributed to cell biology.

3. **Connect the Concept to a Scientist**: The concept of cells leading a double life is associated with the scientist Slythin. He, along with Schwan, contributed to the development of cell theory, which emphasizes that each cell is a living entity and also part of a larger structure (tissue or organism).

4. **Confirm the Answer**: Based on the information about Slythin's contributions, we can conclude that he is the scientist who first proposed the idea that each cell leads a double life.

5. **Select the Correct Option**: Therefore, the correct answer to the question is option A - Slythin.

### Final Answer:
The correct answer is A. Slythin.