dominant allele
the allele that is expressed when present in the heterozygote
Source: Jenkins, John B. 1990. Human Genetics, 2nd Edition. New York: Harper & Row ...
dominant allele
In a heterozygote, the allele that is fully expressed in the phenotype.
dormancy ...
Dominant allele: An allele that masks an alternative allele when both are present (in heterozygous form) in an organism (see recessive).
co-dominant alleles Two different alleles at a locus are responsible for different phenotypes, and both alleles affect the phenotype of the heterozygote.
(The dominant allele must be present in the pair for manifestation of Huntington's.) See id. Suppose the dominant Huntington's allele will be represented by "H," and the recessive allele (which does not cause Huntington's), will be represented by "h.
In the simplest case of a single locus with two alleles: the dominant allele is denoted A and the recessive a. Their frequencies are p and q; freq(A)=p and freq(a)=q.
This is usually done by crossing two members of the same species which possess dominant alleles for particular genes, such as long life and quick metabolism in one organism crossed with another organism possessing genes for fast growth and high yield.
referred to in conjunction with a Punnett square, other types of Mendelian genetics, and frequently contrasted with a dominant pattern of inheritance wherein if one has one copy of the gene, regardless of what the other copy is, that dominant allele ...
Dominant alleles are those that show up in the next generation in crosses between two different "true-breeding strains". The key to any genetics problem is the recessive phenotype (more properly the phenotype that represents the recessive genotype).
25% of their offspring are homozygous for the dominant allele (BB)
50% are heterozygous like their parents (Bb) and
25% are homozygous for the recessive allele (bb) and thus, unlike their parents, express the recessive phenotype.
Selection cannot see it when it is masked by a dominant allele. Many disease causing alleles remain at low frequency for this reason. People who are carriers do not suffer the negative effect of the allele.
recessive Refers to an allele of a gene that is expressed when the dominant allele is not present. An allele expressed only in homozygous form, when the dominant allele is absent.
The phenotype of a genotype containing the dominant allele; the parental phenotype that is expressed in a heterozygote.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ...
The gene whose phenotype is expressed is the dominant allele and the allele whose phenotype is masked is the recessive allele. If the phenotype of the diploid is inte rmediate between that of the two haploid genes, then the alleles are co-dominant.
Females can be carriers of X-linked traits without expressing them because they might carry the dominant allele on the other X chromosome. For example, the following genotype will have a dominant phenotype: XAXa.
Dosage Compensation ...
recessive trait A trait caused by an allele, the phenotype of which is suppressed when it occurs with the dominant allele. Hence, two recessive alleles are necessary for the recessive phenotype to be displayed.
The idea is that these conventional crops will harbor susceptible insects that will mate with resistant insects, diluting out recessive resistance alleles. Of course, if resistance develops as a dominant allele, this strategy will not work.
If the two alleles differ, then one, the dominant allele, is fully expressed in the organism's appearance; the other, the segregate during gamete production. This is the last part of Mendel's generalization.
Recessive -- a gene that is phenotypically manifest in the homozygous state but is masked in the presence of a dominant allele.
 See also: Dominant, Allele, Organ, Recessive, Human
  
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