A genotype is an organism’s complete genome. It is used to refer to a single gene or set of genes, such as the genotype for skin colour. The genes take part in determining the observable characteristics in an organism, such as hair colour, weight, etc.

A phenotype is an individual's observable traits. It is resultant from the interaction of its genotype (total genetic inheritance) with the environment. Examples of observable characteristics are behaviour, colour, shape, and size.

Dominant refers to the relationship between two allelic forms of a gene. Individuals receive two variants of each gene, known as alleles, from either parent. When the alleles of a gene are different, one allele will be expressed; it is the dominant gene and the effect of the other allele, called recessive, is masked. For example, rolling tongue is a dominant trait.