Total number of autosomes in a fertilized egg (zygote) of a human is:

What is $XY$ type of sex determination?

The genes,which are confined to the differential region of the $Y$ chromosome only,are called:

Which of the following exhibits female heterogamety?

$(a)$ 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.

In $Drosophila$,the $XXY$ condition results in a female,whereas in humans,the same condition results in a male with $Klinefelter's$ syndrome. This proves that: