Who for the first time explained that the new cells are derived /formed from pre - existing cells and in which year ?

Options

A. Matthias Scheilden (1838)
B. T.Schwann (1939)
C. C. Nageli (1938)
D. Rudolph Virchow (1855)

Answer

To solve the question of who first explained that new cells are derived from pre-existing cells and in which year, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the scientist who first proposed that new cells come from existing cells and the year this was proposed.

2. **Reviewing Cell Theory**: The cell theory is a fundamental concept in biology that states:
- All living organisms are composed of cells.
- Cells are the basic unit of life.
- New cells arise from pre-existing cells.

3. **Identifying Key Scientists**: The question provides four options:
- A. Matthias Schleiden (1838)
- B. T. Schwann (1939)
- C. C. Nageli (1938)
- D. Rudolf Virchow (1855)

4. **Connecting Scientists to Their Contributions**:
- Matthias Schleiden and Theodor Schwann contributed to the development of cell theory in the 1830s.
- Rudolf Virchow is known for his contribution in 1855, where he stated "Omnis cellula e cellula," meaning all cells arise from pre-existing cells.

5. **Determining the Correct Answer**: Based on the historical context, Rudolf Virchow is the scientist who first explained that new cells are derived from pre-existing cells in 1855.

6. **Final Answer**: Therefore, the correct answer is D. Rudolf Virchow, 1855.