Describe the process of sex determination in humans.

(N/A) The sex-determining mechanism in humans is the $XX: XY$ type.
In humans,out of $23$ pairs of chromosomes,$22$ pairs are exactly the same in both males and females,known as autosomes.
The $23^{\text{rd}}$ pair of chromosomes is the sex chromosome. $A$ pair of $X$-chromosomes $[XX]$ is present in females,while males have one $X$ and one $Y$ chromosome $[XY]$.
During spermatogenesis in males,two types of gametes are produced.
$50\%$ of the total sperms produced carry $X$-chromosomes,and the remaining $50\%$ carry $Y$-chromosomes,in addition to autosomes.
This condition is called male heterogamety.
The $Y$-containing sperms and $X$-containing sperms are called androsperms and gynosperms,respectively.
Females produce only one type of ovum,which contains an $X$-chromosome.
If an ovum is fertilized by a sperm carrying an $X$-chromosome,the zygote develops into a female $[XX]$. If an ovum is fertilized by a sperm carrying a $Y$-chromosome,the resulting zygote will be a male $[XY]$.
Hence,the genetic makeup of the sperm that fertilizes the ovum determines the sex of the child.
There is a $50\%$ chance of having either a male or a female child in each pregnancy.
Thus,it is a chance phenomenon,and women should not be blamed for giving birth to a girl child.