Fertilization can only occurs if :-

Options

A. (1) sperm reaches to the ampullary — isthmjc junction before the ovum.
B. (2) ovum reaches to the ampullary — isthmic junction before sperm.
C. (3) Sperms are transported to the uterus and ovum to the fallopian tube simultaneously.
D. (4) Sperms and ovum are transported simultaneously to the ampullary — isthmic junction

Answer

**Step-by-Step Solution:**

1. **Understanding Fertilization**: Fertilization is the process where a male gamete (sperm) and a female gamete (ovum) unite to form a zygote.

2. **Role of Gametes**: For fertilization to occur, both male and female gametes must be present. The male gamete is the sperm, which is motile and capable of swimming.

3. **Pathway of Sperm**: The sperm travels through the female reproductive tract, starting from the cervix, moving through the uterus, and finally reaching the fallopian tubes.

4. **Key Location for Fertilization**: Fertilization specifically occurs at the ampullary-isthmic junction of the fallopian tube. This is where the sperm and ovum meet.

5. **Simultaneous Arrival**: For fertilization to successfully take place, the sperm and the ovum must arrive at the ampullary-isthmic junction at the same time. If they do not meet simultaneously, fertilization cannot occur.

6. **Conclusion**: Therefore, fertilization can only occur if the sperm and ovum are transported simultaneously to the ampullary-isthmic junction.

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