| A | B |
|---|
| Gene | A small region of a chromosome that contains information about a specific trait |
| Allele | One of two different forms of a gene |
| Homozygous | Describing a genotype in which the individual has two identical alleles of a particular gene (PP; pp) |
| Heterozygous | Describing a genotype in which an individual has two different alleles of a particular gene (Pp) |
| Dominant | An allele that masks the expression of its partner on the homologous chromosome |
| Recessive | An allele whose expression is masked by the expression of its partner on the homologous chromosome |
| Phenotype | A description of an individual in terms of observable traits |
| Genotype | A description of an individual's genetic make-up that specifies which alleles are present |
| Punnett squares | A simple modeling device for predicting the genotypes of all possible offspring when the genotypes of both parents are known |
| Gregor Mendel | the "father" of genetics |
| Chromosome | A long DNA molecule that carries hundreds to thousands of genes |
| Trait | An observable characteristic of an individual |
| Incomplete dominance | A condition in which two non-identical alleles are both expressed, but heterozygotes are a blend of the two phenotypes |
| Gamete | A sexual reproductive cell that contains half a set of chromosomes, one of each homologous pair |
| Codominance | A condition in which two non-identical alleles for a trait are equally expressed; heterozygotes exhibit both forms of the trait |
| Hemophilia | An X-linked recessive trait that results in slow clotting time |
| Karyotype | A chromosome map |
| Pedigree Chart | A "family tree" that traces a trait |
| Genetics | The study of heredity |
| Probability | A branch of mathematics that predicts the likelihood that an event will take place |
