Editing Ploidy (section)

===Zygoidy and azygoidy===
Zygoidy is the state in which the chromosomes are paired and can undergo meiosis. The zygoid state of a species may be diploid or polyploid.<ref>{{cite book |publisher=Academic Press |isbn=978-0-12-017603-8 |last=Books |first=Elsevier Science & Technology |title=Advances in Genetics |date=1950}}</ref><ref name="Cosín-2011">{{cite book |doi=10.1007/978-3-642-14636-7_5  |chapter=Reproduction of Earthworms: Sexual Selection and Parthenogenesis |title=Biology of Earthworms |series=Soil Biology |year=2011 |last1=Cosín |first1=Darío J. Díaz |last2=Novo |first2=Marta |last3=Fernández |first3=Rosa |volume=24 |pages=69–86 |isbn=978-3-642-14635-0 }}</ref> In the azygoid state the chromosomes are unpaired. It may be the natural state of some asexual species or may occur after meiosis. In diploid organisms the azygoid state is monoploid. (See below for dihaploidy.)