Question

In human beings, sex of an individual is determined ___.

• A. during the initial stages of pregnancy
• B. at the time of fertilization
• C. during the later stages of pregnancy
• D. by the environment

Answer 1

The correct option is B

at the time of fertilization

The sex of the child depends on the type of sperm that fertilizes the egg. The egg contains only one X chromosome but half of the sperms released into the female are X- bearing and the remaining half are Y- bearing. It is simply a matter of chance as to which type of sperm fertilizes the ovum. If the egg (having X chromosome) is fertilized by an X-bearing sperm, the resulting combination is XX i.e. female. If the egg (having X chromosome) is fertilized by a Y-bearing sperm, the resulting combination is XY i.e. male.