CBSE Class 10 Answered
The sex of the child is determined genetically in humans.
Women have a perfect pair of sex chromosomes i.e. XX whereas men have a mismatched pair i.e. XY. All eggs produced will carry the X chromosome. Half of the sperms will carry Y chromosome and the other half will carry X chromosome.
During fertilisation, when the egg fuses with a sperm carrying Y chromosome, a boy will be formed On the other hand, when the egg fuses with a sperm carrying X chromosome, the offspring will be a girl child.
Parents XX (Female) XY(Male)
↓ ↓
Gametes X X Y
Female → Male↓ |
X | X |
X | XX (female) | XX(female) |
Y | XY (male) | XY (male) |