Genetics is involved in the determination of the sex of a child. This can be explained as follows: The chromosomes which determine the sex of a child are called sex chromosomes. There are two types of sex chromosomes, one is called X chromosome and the other is called Y chromosome.
(i) A male (man or father ) has one X chromosome and one Y chromosomes, This means that half the male gametes or half the sperme will have X chromosomes and the other half will have Y chromosomes.
(ii) A female (woman or mother) has two X chromosomes (but no Y chromosomes). This means that all the female gametes called ova (or eggs) will have only X chromosomes.
The sex of a child depends on what happens at fertilises :
(a) If sperm carrying X chromsome fertilies an ovum (or egg) which carries X chromosome, then the child born will be a glri (oa female) . This is because the child will have XX combination of sex chromosomes. (b) If a sperm carrying T chromosome fertilises an ovum (or egg) which carries X chromosome, then the child born will be a boy (or male) . This is because the child will have XY conbination of sex chromosomes.
