Raj Kumar and his wife Sunita have been blessed with a baby girl. On the other hand, Kripa Shanker and his wife Vimla have been blessed with a baby boy. What type of sex chromosome has been contributed:
(a) by raj Kumar
(b) by Sunita
(c) by Kirpa Shanker
(d) by Vimla
If X chromosome carrying sperm fuses with an egg cell carrying X chromosome at fertilization, then the zygote will have XX chromosomes and develop into a female child.
In the other case, if Y chromosome carrying sperm fuses with an egg cell carrying X chromosome at fertilization, then the zygote will have XY chromosomes and develop into a male child. Thus, father is responsible for the sex of the unborn child.
(a) Raj Kumar and his wife Sunita have been blessed with a baby girl. It means, X chromosome has been contributed by raj Kumar.
(b) Sunita also contributed X chromosome.
(c) Kripa Shanker and his wife Vimla have been blessed with a baby boy, thus, kripa shanker contributed Y chromosome.
(d) Vimla contributed X chromosome.