Depending on the number of set of chromosome present, they can be categorized. This is called as ploidy. Those are termed as polyploidy which contain either three set or more than that.
In silkworms, there are 10,48,576 ploidy, whereas in human it is deadly and can result in complication in the pregnancy and has to be terminated. Visibility of an extra chromosome can result in a condition which is aneuploidy observed in humans, resulting in disorder such as trisomy 21 or Down syndrome, trisomy 18 or Edwards syndrome and trisomy 13 which is Patau syndrome.
In monosomy, chromosomes are absent, example is Turner syndrome, where female lack chromosome or is dysfunctional. Polyploidy occurs in plants and not in higher animals. Example are African frog, potato, rat in which polyploidy is observed.
In heptaploid, seven chromosome sets are observed. In hexaploidy six sets of chromosomes, five set of chromosomes in pentaploidy, four sets in tetraploidy, three sets in triploidy, in diploid two sets of chromosome and in haploid one set of chromosome.
Humans have a pair of 23 chromosomes, thus 2n = 46. These 23 can be further divided into 22 somatic cell and one sex cell. all the cells in the human body are diploid except the sex cell which consist of egg and sperm and are haploid, with 23 chromosomes. However, these sex cells when fuses they form a zygote which is diploid. Thus, the chromosome number remains stable.
For the formation of sex which are haploid, meiosis occurs and when these sex will tur to diploid after which they will undergo mitosis. Meiosis takes place to form four daughter cell, with each daughter having half chromosome from the parent cell. formation of two daughter cell, where each one contain similar chromosome number. Example are the bees, ants which are developed from meiosis and are known as haploid organism.
Haploid cell possess one chromosome set, whereas the diploid has two sets. Diploid cells further undergo mitosis and haploid cells are formed by meiosis. Example of diploid are somatic cell and that of haploid are sex cells. The daughter cells formed in meiosis are not similar to the parent, whereas in mitosis daughter cells are identical. Eggs and sperm are haploid and skin cells are diploid.