Acrosomal reaction of the sperm occurs due to

Options

A. Its contact with zona pellucida of the ova
B. reactions within the uterine envioronment of the female
C. reactions within the epiddymal 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 that occurs when a sperm cell comes into contact with an egg (ovum). It involves the release of enzymes from the acrosome, a cap-like structure located at the head of the sperm.

2. **Identifying the Trigger**: The acrosomal reaction is specifically triggered when the sperm binds to the zona pellucida, which is the outer protective layer surrounding the ovum.

3. **Mechanism of the Reaction**: Upon binding to the zona pellucida, the acrosome undergoes exocytosis. This means that the contents of the acrosome, which include hydrolytic enzymes, are released.

4. **Role of Hydrolytic Enzymes**: The enzymes released during the acrosomal reaction, such as hyaluronidase, play a vital role in breaking down the layers surrounding the egg. This allows the sperm to penetrate through the corona radiata and reach the plasma membrane of the ovum.

5. **Conclusion**: Based on the understanding of the acrosomal reaction and its mechanism, we can conclude that the correct answer to the question is that the acrosomal reaction of the sperm occurs due to its contact with the zona pellucida of the ovum.

**Final Answer**: The acrosomal reaction of the sperm occurs due to contact with the zona pellucida of the ovum (Option A).

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