punnet squares

allele

An alternative version of a gene.

dominant allele

The allele that determines the phenotype of a gene when the individual is heterozygous for that gene.

F1 generation

The offspring of the P generation.

F2 generation

The offspring of the F1 generation.

genotype

The genetic makeup of an organism.

heterozygous

Having two different alleles for a given gene.

homozygous

Having two identical alleles for a given gene.

P generation

The parent individuals from which offspring are derived in studies of inheritance.

phenotype

The expressed traits of an organism.

punnett square

A diagram used in the study of inheritance to show the results of random fertilization.

recessive allele

An allele that has no noticeable effect on the phenotype of a gene when the individual is heterozygous for that gene.

trait

A variant of a character found within a population, such as purple flowers in pea plants.

true-breeding

Referring to organisms for which sexual reproduction produces offspring with inherited traits identical to those of the parents; the organisms are homozygous for the characteristics under consideration.