Editing Mendelian inheritance (section)

==Non-Mendelian inheritance==
{{main|Non-Mendelian inheritance}}
Mendel himself warned that care was needed in extrapolating his patterns to other organisms or traits. Indeed, many organisms have traits whose inheritance works differently from the principles he described; these traits are called non-Mendelian.<ref>{{cite journal | doi-access=free | doi=10.1016/j.crvi.2016.04.006 | title=Beyond the simplicity of Mendelian inheritance | year=2016 | last1=Schacherer | first1=Joseph | journal=Comptes Rendus Biologies | volume=339 | issue=7–8 | pages=284–288 | pmid=27344551 }}</ref><ref>Khan Academy: [https://www.khanacademy.org/science/biology/classical-genetics/variations-on-mendelian-genetics/a/variations-on-mendels-laws-overview Variations on Mendel's laws (overview)]</ref>

For example, Mendel focused on traits whose genes have only two alleles, such as "A" and "a". However, many genes have [[multiple alleles|more than two alleles.]] He also focused on traits determined by a single gene. But some traits, such as height, depend on many genes rather than just one. Traits dependent on multiple genes are called [[polygene|polygenic traits]].