A certain couple got only four daughters in a row and no son. Does it mean that the husband does not produce Y-bearing sperms? Explain

The two chromosomes that determine the sex of the unborn baby are called sex chromosomes named X chromosomes and Y chromosomes. A female has two chromosomes, while a male has one X and one Y chromosome. The gametes (egg and sperm) have only one set of chromosomes. Thus, in females all the egg cells contain X chromosomes while in males, half sperm have X chromosomes and half sperms have Y chromosomes.

The sex of the child depends upon the kind of sperm that fertilizes the egg. It is simply a matter of chance as to which category of sperm fuses with the ovum. If a couple has only daughter, this means that every time X-bearing sperm of father fertilizes the egg of female. Therefore, it doesn’t mean that the male (husband) does not produce Y-bearing sperms.