Human testes are positioned in an external sac rather than in the abdominal cavity

Options

A. to shorten the distance that semen must travel during ejaculation
B. to shorten the distance that sperm must swim during insemination
C. so that the testes can be kept away from the urinary bladder
D. so that the testes can be kept cooler than the body-s interior

Answer

**Step-by-Step Solution:**

1. **Understanding the Location of Testes:**
- The human testes are located in an external sac known as the scrotum, rather than in the abdominal cavity.

2. **Function of Testes:**
- The primary function of the testes is the production of gametes, specifically sperm.

3. **Temperature Regulation:**
- The production of sperm requires a temperature that is lower than the normal body temperature (approximately 37 degrees Celsius). The optimal temperature for sperm production is about 2-3 degrees Celsius lower than the body temperature.

4. **Reason for External Positioning:**
- The external positioning of the testes in the scrotum allows them to maintain this lower temperature, which is essential for effective sperm production.

5. **Distance Consideration:**
- The scrotum's location also helps in reducing the distance that sperm must travel during ejaculation, ensuring a more efficient reproductive process.

6. **Conclusion:**
- Therefore, the testes are positioned in an external sac (the scrotum) to facilitate sperm production at a suitable temperature and to optimize the distance for sperm travel during ejaculation.

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