Growth of multicellular organisms is initiated by

Options

A. Cell division
B. Cell enlargement
C. Cell differentiation
D. Morphogenesis

Answer

**Step-by-Step Solution:**

1. **Understanding Multicellular Organisms:**
- Multicellular organisms are composed of many cells, which work together to perform various functions. They start their life cycle from a single cell.

2. **Role of Fertilization:**
- The growth of multicellular organisms begins with fertilization, where male and female gametes fuse to form a single cell called a zygote.

3. **Cell Division:**
- After the formation of the zygote, the zygote undergoes a series of cell divisions (cleavage) to proliferate and form multiple cells. This process is known as cell division.

4. **Importance of Cell Division in Growth:**
- Cell division is crucial for the growth of multicellular organisms as it allows the organism to develop from a single cell into a complex structure made up of many cells.

5. **Exclusion of Other Options:**
- **Cell Enlargement:** While cells can enlarge, this process alone does not lead to the formation of multiple cells from a single cell.
- **Cell Differentiation:** This process occurs after multiple cells have formed and is related to the specialization of cells for different functions.
- **Morphogenesis:** This refers to the development of the structure of an organism and is a later stage in development, not the initiation of growth.

6. **Conclusion:**
- Therefore, the correct answer to the question is that the growth of multicellular organisms is initiated by **cell division**.

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