 Contains both dominant AND recessive alleles  Notice, one capital letter and one lower case letter  Examples: Bb Aa Zz Yy Mm

 Contains only dominant OR recessive alleles  Homozygous dominant:  Both Capital letters BB AA ZZ YY  Homozygous recessive:  Both lower case letters bb aa zz yy

 In garden peas, the allele for yellow (Y) is dominant to the allele for green (y)  Write the genotype for homozygous dominant  YY  Write the genotype for homozygous recessive  yy  Write the genotype for heterozygous  Yy or yY (usually written capital letter first) YY yyYy

 In fruit flies, the allele for white eyes (r) is recessive to the allele for red eyes (R)  Write the genotype for homozygous dominant  RR  Write the genotype for heterozygous  Rr  Show a cross between the homozygous dominant and the homozygous recessive

 In cats, the allele for yellow eyes (E) is dominant to the allele for blue eyes (e)  Write the genotype for heterozygous  Ee  Write the genotype for homozygous recessive  ee  Show a cross between two heterozygous

 In vampires, the allele for long fangs(F) is dominant to the allele for short fangs (f)  Write the genotype for a homozygous dominant vampire  FF  Write the genotype for a homozygous recessive vampire  Ff  Show a cross between two heterozygous vampires

 In werewolves, the allele for long hair (h) is recessive to the allele for short hair (H)  Write the genotype for homozygous dominant hair  HH  Write the genotype for heterozygous  Hh