Capacitation refers to changes in the

Options

A. Sperm before fertilisation
B. Ovum before fertilisation
C. Ovum after fertilisation
D. Sperm after fertilisation

Answer

**Step-by-Step Solution:**

1. **Understanding Capacitation**: Capacitation is a physiological process that sperm must undergo in the female reproductive tract before they can fertilize an ovum. Freshly deposited sperm are not immediately capable of fertilization.

2. **Maturation Process**: During capacitation, sperm undergo maturation in the female reproductive tract. This maturation is essential for the sperm to gain the ability to fertilize an egg.

3. **Changes in Sperm Membrane**: The plasma membrane of the sperm undergoes specific changes during capacitation. These changes include:
- Loss of certain proteins.
- Reduction of cholesterol content in the membrane.

4. **Effects of Capacitation**: Capacitation leads to two significant outcomes:
- **Increased Sperm Motility**: After capacitation, sperm become more mobile and swim more vigorously, which is crucial for reaching and fertilizing the ovum.
- **Membrane Fragility**: The sperm membrane becomes more fragile, allowing for easier fusion with the ovum during fertilization.

5. **Conclusion**: Based on the understanding of capacitation and its effects on sperm, we can conclude that capacitation refers to changes in sperm before fertilization.

6. **Final Answer**: Therefore, the correct answer to the question is that capacitation refers to changes in **sperm before fertilization**.

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