| A | B |
|---|
| two-factor cross | a genetic cross that involves two traits |
| dihybrid cross | a genetic cross that involves two traits |
| independent assortment | independent segregation of genes during the formation of gametes |
| incomplete dominance | situation in which one allele is not completely dominant over another |
| codominance | situation in which both alleles of a gene contribute to the phenotype of the organism |
| multiple alleles | three or more alleles of the same gene |
| polygenic traits | trait controlled by two or more genes |
| Thomas Hunt Morgan | an American geneticist working in the early 1900s who decided to use the common fruit fly as his model organism in genetics studies |
| Drosophila melanogaster | the common fruit fly, used as a model organism in genetic studies because it is small and easy to keep, and produces large numbers of offspring in a short period of time |
| albinism | a condition that results when a person has two recessive alleles for the trait of skin color |
