Polyploidy

[pol-ee-ploid] /ˈpɒl iˌplɔɪd/ Biology

adjective
1.
having a chromosome number that is more than double the basic or haploid number.
noun
2.
a polyploid cell or organism.
/ˈpɒlɪˌplɔɪd/
adjective
1.
(of cells, organisms, etc) having more than twice the basic (haploid) number of chromosomes
noun
2.
an individual or cell of this type
n.

1922, from German polyploidie (1910), from polyploid, from Greek poly- (see poly-) + -ploid, from comb. form of ploos “fold” (see fold (v.)) + -oid.

polyploid pol·y·ploid (pŏl’ē-ploid’)
adj.
Having extra sets of chromosomes. n.
An organism with more than two sets of chromosomes.
pol’y·ploi’dy n.
polyploidy
(pŏl’ē-ploi’dē)
The state or condition of being polyploid.
polyploid
(pŏl’ē-ploid’)
Having more than two complete sets of chromosomes. Many plants that are polyploid, such as dandelions, are sterile but can reproduce by apomixis or other asexual means. Other polyploid plants are fertile. For example, durum wheat (Triticum turgidum durum), which is used to make pasta, is tetraploid (it has four sets of chromosomes), while bread wheat (Triticum aestivum) is hexaploid (six sets of chromosomes). Polyploid plants, if viable, are often larger or more productive than diploid plants, and plant breeders often deliberately produce such plants by crossing species or other means. In the animal kingdom, polyploidy is abnormal and often fatal.