The condition of having an abnormal number of chromosomes that isn't a simple multiple of the basic chromosome set.
From Greek 'hetero-' (different) + 'ploid' (from 'ploos' meaning fold). This noun form emerged alongside the adjective in early 20th-century genetics terminology.
Heteroploidy is actually quite common in plants—many crop species are naturally aneuploid, which sometimes gives them desirable traits like disease resistance.
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