The menstrual cycle repeats itself in human females every _____

Options

A. 1 week
B. 28-30 days
C. 4 months
D. 1 year

Answer

**Step-by-Step Solution:**

1. **Understanding the Menstrual Cycle**: The menstrual cycle is a monthly process in which a female's body prepares for a possible pregnancy. It involves the release of an egg (ovum) from the ovaries and the thickening of the uterine lining.

2. **Phases of the Menstrual Cycle**: The menstrual cycle consists of two main phases:
- **Follicular Phase**: This is the first half of the cycle where the egg matures and the uterine lining thickens.
- **Luteal Phase**: This is the second half of the cycle where the body prepares for a potential pregnancy. If the egg is not fertilized, the lining of the uterus is shed, resulting in menstruation.

3. **Duration of the Cycle**: The entire menstrual cycle typically lasts between 25 to 30 days. This means that menstruation occurs approximately every month.

4. **Options Analysis**: The question provides four options:
- 1 week
- 28-30 days
- 4 months
- a year

5. **Correct Answer**: Based on the understanding of the menstrual cycle, the correct answer is **28-30 days**. This is the average duration for the cycle to repeat itself in human females.

**Final Answer**: The menstrual cycle repeats itself in human females every **28-30 days**.

---