| A | B |
|---|
| heredity | passing of traits from parent to offspring |
| trait | physical characteristic |
| purebred | an organism that always produces offspring with the same form of a trait as the parent |
| gene | the factor that controls the trait |
| allele | a different form of a gene. |
| recessive allele | an allele that is masked when a dominant allele is present |
| dominant allele | an allele whose trait always shows up in the organism when the allele is present |
| hybrid | an organism that has two different alleles for the trait |
| probability | the likelihood that a particular event will occur |
| Punnett square | a chart that shows the possible outcomes of a genetic cross |
| phenotype | visible trait (physical appearance) |
| genotype | genetic makeup or allele combinations |
| homozygous | an organism that has two identical alleles for a trait |
| heterozygous | an organism that has two different alleles for a trait |
| codominance | alleles are neither dominant nor recessive |
| meiosis | the process by which the number of chromosomes is reduced by half to form sex cells |
| messenger RNA | a copy of the message in DNA |
| transfer RNA | carries amino acids to the mRNA |
