Acrosomal reaction of the sperm occurs due to

Options

A. its contact with zona pellucida of the ova
B. reactions within the uterine environment of the female.
C. reactions within the epididymal environment of the male.
D. androgens produced in the uterus.

Explanation

### Step-by-Step Solution:

1. **Understanding the Acrosomal Reaction**: The acrosomal reaction is a crucial process in fertilization where the sperm must penetrate the outer layers of the egg (ovum) to achieve fertilization.

2. **Identifying the Structure of Sperm**: The sperm consists of three main parts: the head, neck, and tail. The head contains the nucleus, which houses the DNA, and at the tip of the head is the acrosome.

3. **Role of the Acrosome**: The acrosome is a cap-like structure that contains enzymes, including Acetylcholine, which are essential for breaking down the protective layers surrounding the ovum.

4. **Contact with Zona Pellucida**: The zona pellucida is the glycoprotein layer surrounding the ovum. When the sperm comes into contact with the zona pellucida, the acrosome releases its enzymes.

5. **Digestion of Zona Pellucida**: The enzymes released from the acrosome digest the zona pellucida, allowing the sperm to penetrate the ovum.

6. **Fertilization**: Once the sperm successfully penetrates the zona pellucida, it can enter the ovum, leading to fertilization and the formation of a zygote.

7. **Conclusion**: The acrosomal reaction of the sperm occurs specifically due to its contact with the zona pellucida of the ovum.

### Final Answer:
The acrosomal reaction of the sperm occurs due to its contact with the zona pellucida of the ovum.

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