1. Phenotype
the set of observable characteristics of an individual resulting from their DNA information

2. Genotype:
The genetic information of an individual organism

3. Alleles:
One of two or more alternative forms of a gene that are found at the same place on a chromosome

4. Homozygous:
A word that refers to a particular gene that has identical alleles on both chromosomes.
It is referred to by two capital letters (XX) for a dominant trait, and two lowercase letters (xx) for a recessive trait.

5. Heterozygous:
A word that refers to a particular gene that has different alleles on both chromosomes.
It is referred to by one capital letter and one lowercase letter (Xx)

6. Dominant:
When a trait is dominant, only one allele is required for the trait to be observed. A dominant allele will mask a recessive allele, if present

7. Recessive
When a trait is recessive, an individual must have two copies of a recessive allele to express the trait.
Recessive alleles are denoted by a lowercase letter (a versus A). Only individuals with an aa genotype will express a recessive trait
Offspring must receive one recessive allele from each parent to exhibit a recessive trait