| A | B |
|---|
| heredity | the passing of traits from parent to offspring |
| dominant trait | a feature which is appears in the phenotype of an organism even when a gene for another trait is present. |
| recessive trait | trait which is present in the genotype but does not express itself when a dominant trait is also present. |
| gene | sets of instructions on chromosomes which help determine a trait |
| DNA | heredity molecule which controls all the activities of a cell |
| alleles | the two forms of a gene |
| Punnett square | a diagram used to visualize the possible combinations of an allele from the parents |
| genotype | inherited combination of alleles |
| phenotype | an organism's inherited appearance |
| sex cells | parent cells, the eggs and sperm |
| gametes | sex cells |
| homologous chromosomes | pairs of chromosomes which have similar shapes and genes for similar traits |
| meiosis | cell divison which forms sex cells with half the usual number of chromosomes |
| sex chromosomes | chromosomes which carry genes determining whether an organism is male or female |
