True Breeding- organisms that produce offspring identical to themselves if allowed to self pollinate.

Trait- specific characteristic that varies from one individual to another.

Hybrid- offspring of crosses between parents with different traits.

Genetics- scientific study of heredity.

Gene- sequence of DNA that codes for a protein and thus determines a trait.

Allele- one of a number of different kinds of a gene.

Segregation- separation of alleles during gamete formation.

Gamete- specialized cell involved in sexual reproduction.

Probability- likelihood that a particular event will occur.

Punnett square- diagram showing the gene combinations that might result from a genetic cross.

Homozygous- organism that has two identical alleles for a particular trait.

Heterozygous- organism that has two different alleles for the same trait.

Phenotype- physical characteristics of an organism.

Genotype- genetic makeup of an organism.

Homologous- chromosomes that each have a corresponding chromosome from the opposite sex parent.

Diploid- cell that contains both sets of homologous chromosomes.

Haploid- cell that contains only a single set of chromosomes.

Meiosis- process where the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell.

Tetrad- structure containing 4 chromatids that forms during meiosis.

Crossing-over- homologous chromosomes exchange portions of their chromatids during meiosis.

Gene Map- diagram showing the relative locations of each known gene on a chromosome