| A | B |
|---|
| Phenotype | The physical expression of a gene; brown eyes |
| Genotype | The genes that an individual has; Bb |
| Alleles | A version of a gene; B - brown eyes, b - blue eyes |
| Dominant Allele | An allele that covers up the other allele in a genotype |
| Recessive Allele | The allele that is hidden by the dominant allele in a genotype |
| Homozygous | A genotype that has two of the same alleles |
| Heterozygous | A genotype that has two different alleles |
| True-breeding | An individual with a homozygous genotype |
| Pure bred | An individual with a homozygous genotype |
| Hybrid | An individual with a heterozygous genotype |
| Cross | When two individuals are mated together. |
| Punnett Square | A graphic representation of a genetic cross |
| Co-Dominant | When in a heterozygous genotype are shown in the phenotype |
| Incomplete Dominance | When two alleles in a heterozygous genotype blend to give a phenotype |
| Polygenic | When a phenotype is created from a number of different genes |
| Multiple Alleles | When there are more than two alleles in a population of organisms |
| Complete Dominance | When one allele completely covers up the other allele |
| Sex-linked | When a gene is located on the X-chromosome. |
