alleles

• Allele


  Different versions of the same gene
• Dominant allele


  • Gets expressed even when present with a recessive allele
• Recessive allele


  • Only gets expressed when present in both alleles (homozygous)
• Homozygous


  Having two identical alleles for a particular gene
• Heterozygous


  Having two different alleles for a particular gene
• Heterozygous for fur color


  One allele codes for purple fur, the other for green fur
• The dominant allele gets expressed, not a mix of the two
• Genotype


  The entire collection of alleles an organism has
• Phenotype


  The characteristics an organism displays, determined by its genotype
• Heterozygous and homozygous dominant mice have the same phenotype (purple fur)
• Homozygous recessive mouse has a different phenotype (green fur) than the other two