The fertilization membrane is secreted because

Options

A. It checks the entry of more sperms after fertilization
B. It checks the entry of antigens in ovum
C. It represents the left out tail sperm
D. It represents the plasma membrane of sperm.

Answer

**Step-by-Step Solution:**

1. **Understanding Fertilization**: Fertilization is the process where a sperm cell fuses with an ovum (egg cell) to form a zygote. This typically occurs in the ampulla region of the fallopian tube.

2. **Role of the Acrosome**: The sperm has an acrosome that contains enzymes, such as hyaluronidase, which help in breaking down the protective layers surrounding the ovum, particularly the zona pellucida.

3. **Formation of the Fertilization Membrane**: Once a sperm successfully penetrates the ovum, the vitelline membrane (the outer layer of the ovum) undergoes a transformation to become the fertilization membrane.

4. **Function of the Fertilization Membrane**: The fertilization membrane serves a crucial function by preventing additional sperm from entering the ovum after the first sperm has fertilized it. This is essential to ensure that only one sperm fertilizes the egg, maintaining the correct number of chromosomes.

5. **Evaluating the Options**:
- **Option A**: It checks the entry of more sperms after fertilization. (This is correct.)
- **Option B**: It checks the entry of antigens in ovum. (Not correct; the primary function is to prevent sperm entry.)
- **Option C**: It represents the left out tail sperm. (Not relevant to the function of the fertilization membrane.)
- **Option D**: It represents plasma membrane of sperm. (Incorrect; the fertilization membrane is a separate structure.)

6. **Conclusion**: Based on the explanation above, the correct answer is **Option A**: it checks the entry of more sperms after fertilization.

---