| A | B |
| Heredity | The passing on of characteristics from parents to offspring. |
| Genetics | The branch of biology that studies heredity. |
| Traits | Characteristics that are inherited. |
| Gametes | Another name for sex cells. |
| Fertilization | The uniting of male and female gametes. |
| Dominant | The trait that is observed, opposite of recessive. |
| Recessive | The trait that seems to "disappear". |
| Law of Segregation | Mendel's conclusion that a parent passes on one allele for each trait to its offspring. |
| Phenotype | The way an organism looks. |
| Genotype | The gene combination of an organism, type of genes. |
| Homozygous | Two alleles for the trait are the same, RR. |
| Heterozygous | Two alleles for the trait are different, Rr. |
| Dihybrid cross | A cross with two traits. |
| Monohybrid cross | A cross with one trait. |
| F1 | The first generation. |
| Rr x Rr | 3:1 ratio |
| RrTt x RrTt | 9:3:3:1 ratio |
| Rr x rr | 1:1 ratio |
| Homozygous red, homozygous tall | RRTT |
| Homozygous short | tt |