A recessive gene is one that does not show outwardly unless the organism has two copies of it. If you have only one copy of a recessive gene, your appearance is that of the dominant gene. Here are some sentences.
- Red hair is caused by a recessive gene.
- The baby had two recessive genes for Tay-Sachs disease, and did not live.
- You cannot tell if someone has a recessive gene just by looking at them.