What is the probability of having a male (XY) or female (XX)

Biology · Middle School · Mon Jan 18 2021

Answered on

  • Explanation : The sex of an infant is determined by the type of sex chromosome contributed by the male gamete. A male produces two types of sperms, one type bears 22+X composition and the other, 22+Y. Therefore, a male has 50% sperms with X chromosomes and the other 50% with Y chromosomes.

Anyone of the two types of the sperms can fertilize the egg. If a Y bearing sperm fertilizes the egg, the zygote will be a male (XY) and when X bearing sperm fertilizes the egg, the resulting zygote will be female (XX). Since the ratio of the X chromosome and the Y chromosome in a male gamete is 50:50. The statistical probability of male or female infants is also 50:50.