dominant gene
A gene that is expressed in the offspring whenever it is present
A dominant gene is a gene that, when present in an individual’s genetic makeup, will always manifest its characteristic trait or phenotype, regardless of whether the individual inherited one or two copies of the gene. In other words, a dominant gene will be expressed even if only one copy (from either the mother or father) is present in the genetic makeup of an individual.
For example, consider the gene for blue eye color, which is dominant over the gene for brown eye color. If an individual inherits one copy of the blue eye color gene from one parent and one copy of the brown eye color gene from the other parent, they will have blue eyes because the dominant gene for blue eye color will be expressed. However, if an individual inherits two copies of the brown eye color gene (one from each parent), they will have brown eyes because the dominant gene for blue eye color is not present to be expressed.
The inheritance of dominant genes follows a simple dominant-recessive inheritance pattern that can be predicted using Punnett squares and other genetic tools.
More Answers:
Alleles: Different Versions of Genes and Their Effect on Physical TraitsChromosome Structure and Its Role in Gene Expression and Regulation
Recessive Genes: What You Need to Know.