In the case of mammals, testes are extra abdominal situated in scrotal sacs because

Options

A. there is lack of space in abdomen
B. scrotal sacs have less temperature than abdomen, which is essential for maturation of sperms
C. scrotal sacs have high temperature than abdomen, which is essential for sperm production
D. it helps in easy discharge of sperms during copulation

Answer

**Step-by-Step Solution:**

1. **Understanding the Location of Testes:**
- In mammals, the testes are located in the scrotal sacs, which are situated outside the abdominal cavity.

2. **Reason for Extra-Abdominal Position:**
- The primary reason for the testes being located outside the body is related to temperature regulation. The process of sperm production (spermatogenesis) requires a temperature that is lower than the normal body temperature.

3. **Temperature Requirement for Spermatogenesis:**
- The optimal temperature for sperm production is approximately 2 to 2.5 degrees Celsius lower than the normal body temperature of 37 degrees Celsius. This lower temperature is crucial for the maturation of sperm.

4. **Conclusion:**
- Therefore, the testes are situated in scrotal sacs outside the body to maintain this lower temperature, which is essential for the effective production and maturation of sperm.

5. **Elimination of Incorrect Options:**
- Option 1 (lack of space in abdomen) is incorrect because there is no lack of space.
- Option 3 (scrotal sacs have high temperature) is also incorrect as the temperature in scrotal sacs is lower.
- Option 4 (easy discharge of sperm during copulation) is not relevant to the position of the testes.

6. **Correct Answer:**
- The correct reason for the extra-abdominal position of the testes is that scrotal sacs have a lower temperature than the abdomen, which is essential for sperm maturation.

---