OpenStax
Open Stax: Anatomy & Physiology: Patterns of Inheritance
Students learn about patterns of inheritance including genotype and phenotype, and then learn about the inheritance of autosomal dominant and recessive and sex-linked genetic disorders.
Khan Academy
Khan Academy: Allele Frequency & the Gene Pool
Learn how to find allele frequency and how it's different from genotype frequency.
Khan Academy
Khan Academy: Natural Selection in Populations
How natural selection works at the level of genes, alleles, genotypes, & phenotypes.