Question

The sex chromosomes of both male and female are respectively
A) YY, XX
B) YX, XY
C) XY, XX
D) All of the above

Answer 1

Hint: In the XY sex-determination system, the individuals of a species of animals that are homogametic are generally regarded as the females while those that are heterogametic are regarded as males.

Complete step-by-step answer:
The XY sex-determination system is found in some insects, most mammals, humans, some fishes and snakes, and some plants. In this system, we determine the sex of an individual based on the set of sex chromosomes present in the individual. According to this system of sex-determination females are homogametic i.e. they typically have the same kind of two sex chromosomes that are XX. Similarly, the system calls those individuals as males who are heterogametic i.e. they have two different kinds of sex chromosomes as XY. The two sexes in the Drosophila have been shown below according to the XY system of sex determination –

Figure: Sex determination in insects
In most of the animals, the sex is determined generally through the Y chromosome and the X chromosome is considered as default sex.
So, the correct answer is ‘XY, XX’.

Note: The Y chromosome in humans triggers the male development and if this chromosome is absent, the fetus develops into a female. A gene known as the SRY gene is present on the Y chromosome and is supposed to be responsible for the male development in humans.
Besides the XY system, there are some other systems of sex-determination. One of them is the ZW sex-determination system that is found in birds and some insects.