The middle piece of the sperm contains

Options

A. proteins
B. mitochondria
C. centriole
D. nucleus.

Explanation

**Step-by-Step Solution:**

1. **Understanding Sperm Structure**: The sperm, or spermatozoon, is the male gamete in humans and consists of three main parts: the head, middle piece, and tail.

2. **Identifying the Parts**:
- **Head**: Contains the nucleus and is responsible for fertilization.
- **Middle Piece**: This is the part we are focusing on in this question.
- **Tail**: Helps in the motility of the sperm.

3. **Focusing on the Middle Piece**: The middle piece of the sperm is particularly important for its function. It is known for containing a significant number of mitochondria.

4. **Role of Mitochondria**: Mitochondria are known as the powerhouse of the cell. They provide the necessary energy for the sperm to be motile. This energy is crucial for the sperm to swim through the female reproductive tract to reach the ovum for fertilization.

5. **Conclusion**: Therefore, the middle piece of the sperm contains a large number of mitochondria, which are essential for providing the energy required for the sperm's motility.

**Final Answer**: The middle piece of the sperm contains mitochondria.

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