![Heredity: Crash Course Biology #9](https://i.ytimg.com/vi/CBezq1fFUEA/sddefault.jpg)
Tags:
crashcourse science biology evolution genetics heredity aristotle bloodlines gregor mendel mendelian genetics mendelian trait classical genetics chromosome gene polygenic pleiotropic allele ear wax gene somatic diploid gametes sperm egg haploid polyploid dominance dominant recessive heterozygous homozygous phenotype punnett square reginald c. punnett sex-linked inheritance autosome