Explain the $XO$ and $XY$ types of sex determination.

(N/A) In many insects,the mechanism of sex determination is of the $XO$ type. All eggs bear an additional chromosome besides the autosomes.
On the other hand,some of the sperms bear the $X$ chromosome whereas some do not. Eggs fertilized by sperm having an $X$ chromosome become females and those fertilized by sperms that do not have an $X$ chromosome become males.
Due to the involvement of the $X$ chromosome in the determination of sex,it was designated to be the sex chromosome,and the rest of the chromosomes were named as autosomes. Grasshopper is an example of $XO$ type of sex determination in which the male has only one $X$ chromosome besides the autosomes,whereas females have a pair of $X$ chromosomes $(XX)$.
In many other insects and mammals including humans,$XY$ type of sex determination is observed.
In this type,the number of chromosomes is the same in both males and females. In males,one chromosome is $X$ while the other is distinctly smaller,called the $Y$ chromosome.
Autosomes are present in equal numbers in both males and females.
In males,the chromosomal constitution is $AA + XY$,while in females,it is $AA + XX$.
In humans and Drosophila,males have one $X$ and one $Y$ chromosome in addition to autosomes. Females have a pair of $X$ chromosomes in addition to autosomes.
In both $XO$ and $XY$ types,the male produces two different types of gametes: $(a)$ with or without $X$ $(XO)$,$(b)$ some with $X$ and some with $Y$.
Such a type of sex determination mechanism is designated as the example of male heterogamety.