The testes are situated outside the abdominal cavity within a pouch called scrotum. The scrotum helps in maintaining the low temperature of the testes (2–2.5° C lower than the normal internal body temperature) necessary for spermatogenesis. In adults, each testis is oval in shape, with a length of about 4 to 5 cm and a width of about 2 to 3 cm. The testis is covered by a dense covering. Each testis has about 250 compartments called testicular lobules.
The scrotum is inside the abdominal cavity and maintains normal body temperature for sperm production.
Scrotum is OUTSIDE abdominal cavity. Maintains 2-2.5°C BELOW body temperature. Essential for spermatogenesis.
Scrotum = cooler = 2-2.5°C below = spermatogenesis. Hot = infertile (cryptorchidism).
Assertion (A): The positioning of testes within the scrotum outside the abdominal cavity is essential for male fertility. Reason (R): Spermatogenesis requires a temperature of 2-2.5°C lower than the normal internal body temperature. Additionally, which of the following about testicular structure is CORRECT? S1: Each testis contains approximately 250 testicular lobules. S2: Each testicular lobule contains 3-5 seminiferous tubules. S3: The scrotum helps maintain the low temperature necessary for spermatogenesis.
Correct answer: A — A and R both true; R explains A. S1 and S3 correct.
Assertion TRUE: Scrotal position is essential for fertility. Reason TRUE: Spermatogenesis requires 2-2.5°C below body temperature (NCERT exact). R correctly explains A — the low temperature requirement explains why the testes must be outside the warm abdominal cavity. S1 CORRECT: ~250 testicular lobules per testis. S2 WRONG: Each lobule has 1-3 (not 3-5) seminiferous tubules. S3 CORRECT: Scrotum maintains reduced temperature.
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