diploid(redirected from 2n)
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an organism whose cells have a double (diploid; 2n) set of chromosomes, representing a single (haploid; n) set of paired homologous chromosomes. For example, man has 23 pairs of chromosomes (n = 23’,2n = 46), and an onion has eight pairs of chromosomes (n = 8; 2n = 16). The transition from the diploid state (diplophase) to the haploid (haplo-phase) is accomplished by the first meiotic division, as a result of which the sex cells, or gametes, are formed. When the gametes fuse, the diploid number of chromosomes is restored.