Question

There are five daughters and no son in a family. It may be due to [CPMT 1984]
A) Father produced only X containing sperms
B) Father produced no sperms at all
C) Y type sperms are weaker and not effective
D) By chance each time X sperm fertilized the egg

Answer 1

It may be due to ......D- BY chance each time X sperms fertilzed the egg.

Answer 2

Option D) By chance each time X sperm fertilized the egg.

• The fertilization of a male gamete and a female gamete is not a predefined action. Rather this event takes place by chance.
• The probability of 1 sperm out of millions of sperms to fuse with 1 egg out of 80,000 eggs is not possible to determine.
• Half of the sperms have an X chromosome while the other half has a Y chromosome.
• Each egg will always have only one chromosome i.e. X chromosome.
• Therefore by chance, an X chromosome is fusing with the egg to form XX zygote which results in a daughter.