| A | B |
| Heterozygous | Genotype with 2 different alleles |
| Homozygous | Genotype with 2 of the same type of allele |
| Allele | A specific version of a trait |
| Homozygous Dominant | Two capital letters |
| Homozygous recessive | Two recessive letters |
| Homozygous dominant and Heterozygous | Results in a dominant phenotype |
| Phenotype | What is "expressed" |
| Genotype | What alleles are present in an organism's chromosomes |
| Dominant allele | Will be shown if present |
| Recessive allele | Will be hidden unless "pure" |
| Sex Linked Trait | A trait which is determined by a gene found on the X chromosome of the Sex Chromosomes |
| Sex Chromosomes | The 23rd pair of chromosomes-- XX or XY |
| Male | Has sex chromosomes XY |
| Female | Has sex chromosomes XX |