CBSE Class 10 Science 2020 · Paper 31/4/1 · Question 28(b)

(a) Puberty is the period during adolescence when the reproductive tissues begin to mature, that is, the age at which the reproductive organs of boys and girls become functional. (b) (i) Testes: produce the sperms and secrete the male sex hormone testosterone. (ii) Seminal vesicle: secretes a fluid in which the sperms are carried; this fluid makes their transport easier and provides them with nutrition. (iii) Vas deferens: carries the sperms from the testes; the duct of the seminal vesicle joins it, and it delivers the sperms into the urethra. (iv) Urethra: forms a common passage for both the sperms and the urine, and carries the sperms out of the body. (c) Sperm formation requires a temperature lower than the normal body temperature, so the testes lie outside the abdominal cavity, in the scrotum, which is about $2$ to $2.5^{\circ }$C cooler. (d) Each sperm has a long tail, and by moving it the sperm swims through the fluid towards the female germ cell.