Question

(4) How is sex determined of a foetus?​

Answer 1

SEX DETERMINATION OF FOETUS:

• The male parent has genotype XY

• The female parent has genotype XX

Now, the sex chromosomes donated from the gametes of the parents are as follows:

• From male: X or Y

• From female: Only X

Now, let's see a PUNNETT SQUARE:

$\begin{array}{| c | c | c |}\cline{1-3} M/F & X & Y \\\cline{1-3} X & XX (girl) & XY (boy) \\\cline{1-3} X & XX (girl) & XY (boy) \\\cline{1-3}\end{array}$

• So, there is 50% chance of male and 50% chance of female being born.

However, it should be noted that:

• The genotype of the child is determined mainly the chromosomes donated from male parent.