A section of piece of DNA that codes for a specific trait.

Different forms of genes

Both alleles for a trait are the same and dominant

Both alleles are the same and recessive

One allele for a trait is dominant and the other allele is recessive.

The genetic makeup of an organism. The genes it has.

The physical appearance of an organism

A chart that shows all the possible combinations of alleles that can result from a genetic cross between two parents.

An allele that is always expressed when present

An allele that is only expressed when the dominant allele is not present.

The resulting offspring have a phenotype that is a blending of the parental traits. Black and white make gray

The resulting offspring have a phenotype that fully expresses both parental traits. Black and white make checkered or spotted

Occurs when multiple genes determine the phenotype of a trait

Three or more forms of a gene that code for a single trait