null allele(redirected from Null alleles)
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null alleleA segment of DNA which is not known to encode a protein product.
null allelea form of a gene whose product is either absent at the molecular level, or is present but has no measurable phenotypic function. For example, in a heterozygote with INCOMPLETE DOMINANCE one gene form is a ‘null allele’ and is inactive, while the other allele is unable to compensate for the null allele and so produces an intermediate phenotype.
one of two or more alternative forms of a gene at the same site or locus in each of a pair of chromosomes, which determine alternative characters in inheritance. Called also allelomorph.
an allele which produces an antigen which cannot be detected.
see silent allele (below).
one that produces no detectable effect.