Genes that are positioned so close on the same chromosome, that chances of crossing-over between these genes is virtually zero. Hence recombinant gene combinations do not occur between absolutely linked genes.
Synonyms: linked genes (narrow definition), absolute coupled genes
RT: (broad definition) linked genes >> (narrow definition) absolutely linked genes
ST: coupling phase ↔ repulsion phase
ST: sex-linked genes
RT: crossing-over
RT: pleiotropy