Answer
The normal body cells ( no-reproductive or non-germ cells) of an animal has a characteristic number of chromosomes in each nucleus. This number is diagnostic and species specific . In humans that number is a total of 46 per nucleus. This is the diploid number of chromosomes for humans and any body cell that does not have 46 chromosomes by definition not a human cell. The 46 chromosomes ( human 2n or diploid number) is not just a random and undifferentiated group of chromosomes. There are two major sub-divisions : first, there are autosomes and sex chromosomes ; second, there homologs and non-homologs. There are 22 pairs of chromosomes that concerned wit ordinary body structure and physiology; these are the autosomes or non-sex chromosomes; the pair of chromosomes are the sex chromosomes and may be present in a nucleus as two Xs (XX) for a female cell or as anX and a Y chromosome (XY) for a male cell.
Work Step by Step
The 46 chromosomes of a normal human body or somatic cell comprise a st of 23 from the paternal parent and 23 from the maternal parent. These cells with half the normal number of chromosomes are called germ cells (sperms and ova) and are said to have the haploid number ( from the Grk. haploeides, single) of chromosomes. At sexual reproduction when male and female gametes join to for zygotes this single set of chromosomes (n) is doubled and the species specific number of chromosomes (2n) is reconstituted. The haploid set of chromosomes contains one member of each pair of the autosomes of the diploid set ( or multiple in a somatic cell). The diploid set of chromosomes are replicated during regular mitosis. The homologous pairs are similar in shape , size, centromere locations and gene loci i.e. except for X in any male cells. Haploid cells are formed in the first meiotic division and have half the diploid number of chromosomes of somatic cells
