Genetics

•  Alleles: different versions of the same gene (one version of each homologous chromosome pair) found in the same locus or location on each chromosome.
•  Genotype: the combination of alleles in an individual's genome
• Phenotype: the traits that are expressed as a result of an individual's genotype and interaction with their environment
• Meiosis builds haploid gametes whose genotypes are different from their parent cells
• Alleles in a gene pair are the same = individual is homozygous for that trait
• Genes in gene pair are different = individual is heterozygous for that trait
• A recessive allele is not represented unless individual is homozygous recessive.
• A dominant allele will be expressed (visible) if an individual is homozygous dominant or heterozygous
• 1. Law of segregation 

  Each gamete contains only one allele for each gene, each parent can only pass on 1 version of each gene. (This occurs during meiosis 1)
• Law of Independent Assortment 

  Alleles are segregated (divided) randomly.(Exception: alleles located on the same chromosome cannot be randomly separated) This occurs during meiosis 1.
• 1. Law of Dominance 

  Recessive alleles are masked (not expressed) by dominant alleles. (Exception: some alleles are codominant or incompletely dominant