Homogametic, as the name suggests, refers to organisms producing the same gametes.
Homogametic individuals carry matching pairs of sex chromosomes, whereas heterogametic individuals carry sex chromosomes of different types.
In humans, females are homogametic, whereas males are heterogametic because females have two identical sex chromosomes (XX), and males have an X and a Y (XY) chromosome.
At the time of fertilization, random fusion takes place. If sperm with 22A+X fuses with the egg which has 22A+X, the zygote will have a 44A +XX condition. Such a zygote forms a female.
In contrast, if sperm carrying 22A+Y unites with the egg, the zygote will have 44A+XY. Such a zygote forms a male child.
This mechanism of chromosomal sex determination is called the XX – XY mechanism of the female homogametic and male heterogametic systems.
This type of sex determination is present in mammals, including humans, plants, and many insect species like Drosophila, etc.