The mitotic division starts as the zygi\oge moves through the of the oviduct called cleavage.

Options

A. Ampulla
B. Isthmus
C. Fimbriae
D. Infiundibulum

Answer

**Step-by-Step Solution:**

1. **Understanding the Zygote and Cleavage**: The zygote is formed when a sperm fertilizes an egg. After fertilization, the zygote begins to divide through a process called cleavage, which involves mitotic divisions.

2. **Location of Cleavage**: The zygote travels through the oviduct (also known as the fallopian tube) after fertilization. The cleavage process starts as the zygote moves through a specific section of the oviduct.

3. **Identifying the Oviduct Sections**: The oviduct consists of several parts:
- **Fimbriae**: The finger-like projections that help guide the egg.
- **Infundibulum**: The funnel-shaped end of the oviduct.
- **Ampulla**: The widest part of the oviduct where fertilization typically occurs.
- **Isthmus**: The narrow section of the oviduct that connects to the uterus.

4. **Cleavage Occurrence**: The cleavage begins in the isthmus of the oviduct. This is where the zygote undergoes mitotic divisions as it moves towards the uterus.

5. **Conclusion**: Therefore, the correct answer to the question is that the mitotic division starts as the zygote moves through the isthmus of the oviduct.

**Final Answer**: The mitotic division starts as the zygote moves through the isthmus of the oviduct.

---