overdominance
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Related to overdominance: Multiple alleles
overdominance
[¦ō·vər′däm·ə·nəns] (genetics)
Monohybrid heterosis, that is, the phenotype is being more pronounced in the heterozygote than in either homozygote with respect to a specified pair of alleles.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.