Which part of the sperm plays an important role in penetrating the egg membrane?

Options

A. allosome
B. tail
C. autosome
D. acrosome

Explanation

To answer the question "Which part of the sperm plays an important role in penetrating the egg membrane?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: We need to identify which part of the sperm is responsible for penetrating the egg membrane. This is crucial for fertilization.

2. **Identifying the Parts of the Sperm**: The sperm has several parts, including:
- Head
- Midpiece
- Tail
- Acrosome (a specialized structure on the head)

3. **Understanding Egg Membranes**: The egg has multiple layers of membranes that need to be penetrated for fertilization. This is to prevent polyspermy, which is the fertilization of an egg by more than one sperm.

4. **Evaluating the Options**:
- **Allosome**: This is not a part of the sperm.
- **Tail**: The tail is responsible for the movement of the sperm but does not penetrate the egg.
- **Autosome**: This is also not a part of the sperm.
- **Acrosome**: This is a cap-like structure on the head of the sperm that contains digestive enzymes.

5. **Role of the Acrosome**: The acrosome releases enzymes that help break down the egg's protective layers, allowing the sperm to penetrate and fertilize the egg.

6. **Conclusion**: Based on the evaluation, the part of the sperm that plays an important role in penetrating the egg membrane is the **acrosome**.

### Final Answer:
The correct answer is **the acrosome**.

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