how many chromosomes does a human diploid cell have
Ploidy Humans are diploid organisms, carrying two complete sets of chromosomes: one set of 23 chromosomes from their father and one set of 23 chromosomes from their mother. The two sets combined provide a full complement of 46 chromosomes. This total number of chromosomes is called the chromosome number. The zygotic number is defined as the number of chromosomes in zygotic cells. Human zygotes are diploid, hence with a zygotic number of 46.
Karyotype The work took place in 1955, and was published in 1956. The karyotype of humans includes only 46 chromosomes.[15][16] Rather interestingly, the great apes have 48 chromosomes. Human chromosome 2 is now known to be a result of an end-to-end fusion of two ancestral ape chromosomes.[17][18]
Karyotype The basic number of chromosomes in the somatic cells of an individual or a species is called the somatic number and is designated 2n. In the germ-line (the sex cells) the chromosome number is n (humans: n = 23).[2]p28 Thus, in humans 2n = 46.
Meiosis Because the number of chromosomes is halved during meiosis, gametes can fuse (i.e. fertilization) to form a diploid zygote that contains two copies of each chromosome, one from each parent. Thus, alternating cycles of meiosis and fertilization enable sexual reproduction, with successive generations maintaining the same number of chromosomes. For example, diploid human cells contain 23 pairs of chromosomes including 1 pair of sex chromosomes (46 total), half of maternal origin and half of paternal origin. Meiosis produces haploid gametes (ova or sperm) that contain one set of 23 chromosomes. When two gametes (an egg and a sperm) fuse, the resulting zygote is once again diploid, with the mother and father each contributing 23 chromosomes. This same pattern, but not the same number of chromosomes, occurs in all organisms that utilize meiosis.