A physical characteristic like eye color.

A small part on a chromosome that controls a trait.

The scientific study of genes.

A purebred is an organism such as a plant, that always produces offspring with the same form of a trait as the parent.

The different forms of a gene, like a small stem or a tall stem.

A dominant allele is one whose trait always shows up in the organism when the gene is present.

A recessive allele is one that is masked whenever the dominant allele is present.

A hybrid is an organism that has both a dominant and a recessive allele for the same gene (trait)

Probability is the likelihood that an event will happen (the odds). The odds that a certain event will happen.

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

An organisms phenotype is its physical appearance, or its visible traits.

An organisms genotype is its genetic makeup, or actual allele combinations.

An organism that has two identical alleles for the same trait is said to be homozygous for that trait.

An organism that has two different alleles for the same trait is said to be heterozygous for that trait.

For some alleles, an inheritance pattern called codominance exists. In codominance, the alleles are neither dominant nor recessive. Both examples of the trait will show up.