Which one among the following is absent in human sperm?

Options

A. Nucleus
B. Mitochondria
C. Endoplasmic reticulum
D. Centriole

Answer

**Step-by-Step Solution:**

1. **Understanding the Components of Human Sperm**:
- Human sperm consists of several parts: the head, midpiece, and tail. Each part has specific organelles that perform various functions.

2. **Identifying the Organelles Present in Sperm**:
- The **nucleus** is located in the head of the sperm and contains the genetic material.
- The **mitochondria** are found in the midpiece of the sperm and provide energy for motility.
- The **centriole** is present in the neck region of the sperm and plays a role in cell division and the formation of the tail.

3. **Determining the Absent Organelle**:
- The **endoplasmic reticulum (ER)** is a network of membranes involved in protein and lipid synthesis. In the case of human sperm, it is not present.

4. **Conclusion**:
- Among the options given, the endoplasmic reticulum is the organelle that is absent in human sperm.

**Final Answer**: The endoplasmic reticulum is absent in human sperm.

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