Cellular totipotency was first demonstrated by:

Options

A. T. Schwann
B. A.V Leeuwenhoek
C. F.C steward
D. Robert Hooke.

Answer

**Step-by-Step Solution:**

1. **Understanding Cellular Totipotency**: Cellular totipotency refers to the ability of a single cell to divide and develop into a complete organism. This means that totipotent cells can give rise to all cell types, including both the somatic and germ cells.

2. **Identifying the Scientist**: The question asks who first demonstrated cellular totipotency. We need to evaluate the options provided: T. Schwann, Anton von Leeuwenhoek, Epstein-Stewart, and Robert Hooke.

3. **Evaluating the Options**:
- **T. Schwann**: Known for formulating the cell theory, but not for totipotency. Thus, this option is incorrect.
- **Anton von Leeuwenhoek**: Recognized as the father of microbiology and known for his work with microscopes, but he did not demonstrate totipotency. This option is also incorrect.
- **Epstein-Stewart**: This is the correct option as it is stated that F.C. Stewart demonstrated cellular totipotency.
- **Robert Hooke**: Famous for discovering cells but not for totipotency. Therefore, this option is incorrect as well.

4. **Conclusion**: Based on the evaluation, the correct answer is Epstein-Stewart, who first demonstrated cellular totipotency.

**Final Answer**: Cellular totipotency was first demonstrated by Epstein-Stewart.

---