Question

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

• 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 1

The correct option is B Scrotal sacs have less temperature than abdomen, which is essential for maturation of sperms.

In man, the testes are paired oval bodies about 4 - 5 cm in length. The testes develop in the pelvic cavity but by the time the baby is born, they move out of the abdominal cavity, and lie in a pouch of skin called as scrotum. The scrotum hangs between the thighs. The testes are extra - abdominal because sperms mature at a temperature slightly lower than the body temperature. The scrotal sac is filled with a fluid called as hydrocoel. The scrotal sacs act as thermoregulators and keep the testicular temperature 2${}^o$C lower than body temperature for normal spermatogenesis. The cavity of the testes is called as vaginal coelom and it is connected to the abdominal cavity through inguinal canal.

Therefore, the correct answer is option B.