Questions About Cancer? 1-800-4-CANCER

Understanding Cancer Series

  • Posted: 01/28/2005
  • Reviewed: 09/01/2006

Slide 26

:

Alleles

All genotypes are not created equal in their influence on phenotype. Genes come in many varieties called alleles, and some are more dominant than others. In a pair of alleles, the effect of a dominant allele prevails over the effect of a recessive allele. And the effects of a recessive allele become apparent only if the dominant allele becomes inactivated or lost.

Alleles