A recessive trait is a characteristic that appears in an individual only if the dominant form of the gene governing the characteristic is not present. Recessive traits are governed by recessive genes. A recessive gene can be masked by a dominant one.
Organisms must contain two recessive genes before the recessive trait is seen in the individual. Examples of recessive traits include blue eyes, straight hair, attached earlobes, albinism, baldness and congenital deafness.
Organisms carry several forms, or alleles, of genes. Some alleles are dominant over others, meaning that as long as an individual has one dominant allele, that characteristic can be expressed. Each individual has two alleles for each gene, one coming from each parent. With dominant traits, characteristics governed by dominant alleles, an individual carries either two dominant genes or one dominant and one recessive gene. A dominant gene can be expressed even if only one copy of the gene is present.