Diploidy and Haploidy :: In the chromosomal complement given species not all the chromosomes are different from each other .In fact these are in pairs ,i.e. every two chromosomes of the karyotype are similar in shapes size and structure or say are homologous, Obviously the chromosomes of one pairs are different from those of every other pair. This means that the karyotype in fact comprises two similar sets of chromosomes, Hence it is called diploid )2x or 2n,)
In sexual reproduction ,union of two different sex cells or gametes (male gamete or sperm cell and female gamete or ovum) occur to form a single diploid cell called zygote. From the zygote, all body cells of a new individual arise by repeated mitotic divisions. Thus the karyotypic diploid chromosomal complement is transmitted to all body cells. However to prevent multiplication of the diploid complement the sex cells must contain only half the number or say a single set or chromosomes .This gametic chromosomal complement is thus, haploid (x or n) and called genome, in contrast to the karyotype of diploid somatic cells, Obviously of the two sets of chromosomal in a karyotype in every individual, one is originally obtained from male and the other female parents.