NEET2018ZoologyPrinciples of Inheritance and VariationActual
Assertion : In humans, the gamete contributed by the male determines whether the child produced will be male or female. Reason: Sex in humans is a polygenic trait depending upon a cumulative effect of some genes on X -chromosome and some on Y-chromosome.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
C. If assertion is true but reason is false.
Step-by-step solution
Sex chromosomes in the human female are XX; whereas those of the male are XY. During the very early stages of gestation period, the development of the embryo is predisposed in certain directions by the possession of the sex chromosomes one contributed by the mother and the other by the father. The mother can contribute only X chromosome which predisposes towards the development of female structural, functional and temperamental characteristics, but the father can contribute either an X or a Y chromosome predisposin