Function

• When a trait is discrete, that is, when you can only have one of a fixed number of types of that trait, the trait is often determined by which gene is dominant and which is recessive. The classic example is eye color, where brown eyes are dominant and all other colors are recessive.
  
  If the brown eye gene is labeled as "B" and other colors as "o" (lower case letters are usually used for recessive genes), then a person receives one gene from each parent, so they can end up with "BB," "Bo," "oB" or "oo." Dominance means that, unless you get "oo," the person's eyes will be brown.
  
  

Examples

• Blinn College has made a list of some examples of dominant and recessive genes. In addition to eye color, dark hair is dominant over light color hair, curly hair is dominant over straight hair, and freckles are dominant over a lack of freckles.
  
  

Exceptions

• Traits that are continuous, such as height, are not determined by dominant vs. recessive genes. Height is related to both parents' height.