Dominant allele: Difference between revisions

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A dominant allele is one copy of the gene that will always be expressed whether homozygous or heterozygous. The phenotype of the organism will show the dominant trait whenever this allele is present.  
A dominant [[Allele|allele]] is one copy of the gene that will always be expressed whether [[Homozygous|homozygous]] or [[Heterozygous|heterozygous]] for the gene. The phenotype of the organism will show the dominant trait whenever this allele is present.  


Dominant alleles are often&nbsp;designated a capital&nbsp;letter for example (Ww) - here the W represents the dominant&nbsp;wildtype&nbsp;allele whilst w is the recessive allele. <ref>Hartl. D and Ruvolo. M, (2012) Genetics. Analysis of Genes and Genomes, 8th Edition, Burlington: Jones &amp;amp;amp;amp; Barlett Learning.</ref> <gallery>Hartl. D and Ruvolo. M, (2012) Genetics. Analysis of Genes and Genomes, 8th Edition, Burlington: Jones & Barlett Learning.</gallery>
Dominant alleles are often&nbsp;designated a capital&nbsp;letter for example (Ww) - here the W represents the dominant&nbsp;[[Wild - type|wildtype]]&nbsp;allele whilst w is the [[Recessive|recessive allele]]<ref>Hartl. D and Ruvolo. M, (2012) Genetics. Analysis of Genes and Genomes, 8th Edition, Burlington: Jones and Barlett Learning.</ref>.


(WW) - Homozygous dominant (W phenotype expressed)  
(WW) - Homozygous dominant (W phenotype expressed)  


(Ww) - Heterozygous (W phenotype expressed)  
(Ww) - Heterozygous (W phenotype expressed - due to the dominant allele masking the expression of the recessive allele).&nbsp;


(ww) - Homozygous recessive (w phenotype expressed)
(ww) - Homozygous recessive (w phenotype expressed)  
 
=== References  ===
 
<references />

Latest revision as of 18:09, 22 October 2018

A dominant allele is one copy of the gene that will always be expressed whether homozygous or heterozygous for the gene. The phenotype of the organism will show the dominant trait whenever this allele is present.

Dominant alleles are often designated a capital letter for example (Ww) - here the W represents the dominant wildtype allele whilst w is the recessive allele[1].

(WW) - Homozygous dominant (W phenotype expressed)

(Ww) - Heterozygous (W phenotype expressed - due to the dominant allele masking the expression of the recessive allele). 

(ww) - Homozygous recessive (w phenotype expressed)

References

  1. Hartl. D and Ruvolo. M, (2012) Genetics. Analysis of Genes and Genomes, 8th Edition, Burlington: Jones and Barlett Learning.