| A | B |
|---|
| hybrid | another name for heterozygous; has a capital letter and a small letter |
| heterozygous | another term for hybrid; Xx; has two different alleles for a trait |
| allele | an alternate form of a gene |
| homozygous | having the same allele for a particular trait; TT or tt are examples |
| gene | segment of DNA that codes for a particular trait or protein |
| F2 generation | second filial generation; the "grandchildren" |
| F1 generation | first filial generation; the "children" |
| P generation | parental generation |
| codominance | type of inheritance where both traits are expressed at the same time; ex: roan horse |
| dominant | the allele that is expressed most often |
| pure | another name for homozygous; contains the same allele for a trait; TT or tt |
| incomplete dominance | a blending of traits in the F1; ex: pink snapdragons |
| recessive | describes a trait that is "hidden" by the dominant gene; seen in the F2 |
| test cross | used to determine the genotype of an unknown individual; cross the individual with a homozygous recessive individual |
| punnett square | diagram used to predict the genotypes of offspring |
| genotype | expressed as DD, Dd or dd; the actual genes of the organism |
| phenotype | the appearance of the trait in an individual; ex: curly hair or blue eyes |
| pedigree | used to interpret patterns of inheritance within a family |
| genetics | the field of biology devoted to understanding how characteristics are transmitted from parents to offspring |
| heredity | the transmission of characteristics from parents to offspring |
| trait | a genetically determined variant of a characteristic, such as yellow flower color |
| law of segregation | Mende's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete |
| independent assortment | the random distribution of the pairs of genes on different chromosomes to the gametes |
| probability | the likelihood that a possible future event will occur in any given instance of th event |
| monohybrid cross | a cross between individuals that involves one pair of contrasting traits |
| complete dominance | a relationship in which one allele is completely dominant over another |
| codominance | a condition in which both alleles for a gene are expressed |
| dihybrid cross | a cross between individuals that involves two pairs of contrasting traits |
