What are dominant and recessive genes?

Dominant genes are those that express their traits even if only one copy is present, while recessive genes require two copies to express their traits.

In the study of genetics, genes are the basic units of heredity that determine specific traits or characteristics in an organism. These genes come in pairs, one from each parent, and their interaction determines the traits that an organism will exhibit.

Dominant genes are those that are always expressed, regardless of the gene they are paired with. This means that if an organism has at least one copy of a dominant gene, the trait that the gene codes for will be visible in the organism. For example, in humans, the gene for brown eyes is dominant. So, if a person has at least one copy of the brown eye gene, they will have brown eyes.

On the other hand, recessive genes are those that are only expressed when two copies of the gene are present, one from each parent. If an organism has only one copy of a recessive gene, the trait will not be visible because it is masked by the dominant gene. However, the organism is a carrier of the recessive gene and can pass it on to its offspring. For instance, the gene for blue eyes in humans is recessive. This means that a person will only have blue eyes if they inherit the blue eye gene from both parents.

In summary, the difference between dominant and recessive genes lies in their expression. Dominant genes express their traits even if only one copy is present, while recessive genes require two copies to express their traits. This fundamental concept in genetics helps us understand how traits are passed from parents to offspring and why we exhibit certain characteristics.