1. Education
You can opt-out at any time. Please refer to our privacy policy for contact information.

Discuss in my forum

Heterozygous - A Genetics Definition


Detail image of fresh English Peas
Matthew O'Shea/Photodisc/Getty Images
Definition: Heterozygous refers to having two different alleles for a single trait.

Related Terms: Allele, Genes, Homozygous
The gene for seed shape in pea plants exists in two forms, one form or allele for round seed shape (R) and the other for wrinkled seed shape (r). A heterozygous plant would contain the following alleles for seed shape: (Rr).

Organisms have two alleles for each trait. When the alleles of a pair are heterozygous, one is dominant and the other is recessive. Using the previous example, round seed shape (R) is dominant and wrinkled seed shape (r) is recessive. Round: (RR) or (Rr), Wrinkled: (rr).

Related Resources: Chromosomes and Gender, Law of Segregation, Independent Assortment
  1. About.com
  2. Education
  3. Biology
  4. Biology Dictionary
  5. Genetics Glossary
  6. Heterozygous - A Genetics Definition

©2014 About.com. All rights reserved.