Question

In human beings, the statistical probability of getting either a male or female child is 50 : 50. Give a suitable explanation.

NCERT Class X
Science - Exemplar Problems

Chapter_Heredity and Evolution

Answer 1

The sex of the baby depends on the chromosome contributed by the father......the females carry only the X chromosome while males have both X&Y chromosome so, if the father gives an x chromosome (XX) the baby will be a girl and if the father donates Y Chromosome (XY) the will be a boy......so the probability is 50-50 for the sex of the baby..hope it helps u

Answer 2

Females have two X chromosomes in their cell.Males have one X chromosome and one Y chromosome in their cell .If the sperm carries X chromosomes and fertilize with the ovum the resultant baby will have XX condition.So the baby will be a girl.If the sperm carries Y chromosomes and fertilize with the ovum the resultant baby will have XY condition. S o the resultant baby will be a boy. So their will be 50 50 chances . that will be decided by the father.