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.
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
If the Assertion is correct but Reason is incorrect.
If both the Assertion and Reason are incorrect.
While solving the problem of sex determination in large number of insects, it was observed that
$(a)$ In humans, males are heterogametic and females are homogametic. Explain. Are there any examples where males are homogametic and females heterogametic ?
$(b)$ Also describe as to who determines the sex of an unborn child ? Mention whether temperature has a role in sex determination.
A family has five girls and no son. Probability of son as the $6^{th}$ child will be
In man the normal number of chromosomes is
In man, the composition of female destined zygote is