In human males testes lie in scrotum outside abdominal cavity. What will be the effect if testes fail to descend and remain in the abdomen?

Explanation

**Step-by-Step Solution:**

1. **Understanding Testes Development**: In human males, the testes are initially formed in the abdominal cavity during fetal development. As the fetus grows, the testes normally descend into the scrotum before birth.

2. **Importance of Testes Location**: The scrotum is located outside the abdominal cavity, which is crucial for the process of spermatogenesis (the production of sperm). This is because spermatogenesis requires a temperature that is slightly lower than the normal body temperature.

3. **Temperature Requirement for Spermatogenesis**: The optimal temperature for spermatogenesis is about 2 degrees Celsius lower than the normal body temperature. The scrotum provides this cooler environment, which is essential for the development and maturation of sperm.

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