Site of formation of zygote in human beings is

Options

A. Isthmus
B. Ampullary - isthmic junction
C. Uterus
D. Infundibulum

Answer

### Step-by-Step Solution:

1. **Understanding Zygote Formation**: The zygote is formed when a sperm (male gamete) fertilizes an ovum (female gamete). This process is known as fertilization.

2. **Pathway of the Ovum**: The ovum is released from the ovary and enters the fallopian tube. It first travels through the infundibulum, which is the funnel-shaped opening of the fallopian tube.

3. **Movement of the Ovum**: After entering the infundibulum, the ovum moves towards the ampulla, which is the wider section of the fallopian tube.

4. **Pathway of the Sperm**: During insemination, sperm are deposited in the female genital tract. They travel through the cervix into the uterus and then towards the fallopian tube.

5. **Meeting Point of Sperm and Ovum**: The sperm and ovum meet at the junction of the ampulla and isthmus of the fallopian tube. This is the specific site where fertilization occurs.

6. **Formation of the Zygote**: Upon the fusion of the sperm and ovum at the ampulla-isthmus junction, a single-celled diploid zygote is formed.

7. **Conclusion**: Therefore, the site of formation of the zygote in human beings is the **ampulla-isthmus junction** of the fallopian tube.

### Final Answer:
The site of formation of the zygote in human beings is the **ampulla-isthmus junction** of the fallopian tube.

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