A recessive allele refers to a gene variant that is overshadowed or hidden when another dominant allele is also present. In order for the recessive allele to have an effect, it needs to be inherited from both parents. Full definition
Because the sire and dam share 2 recent common ancestors, CMS is likely the result of recessive alleles inherited identical by descent (IBD). (journals.plos.org)
My family history doesn't have much in the way of rare inherited syndromes, but that doesn't mean I'm not a carrier of one or two recessive alleles for something like cystic fibrosis. (massgenomics.org)
The relatively high estimates of the frequencies of the unfavourable recessive alleles in each breed, especially for hip dysplasia, suggest that it would be possible to gain considerable genetic progress by selection against a major gene. (nature.com)