nonconditional mutanta MUTANT that displays the mutant PHENOTYPE under all conditions. Where the activity of a GENE product is completely eliminated the mutant is a null mutant (see NULL ALLELE). Where the mutant retains some activity of the product it is called a leaky mutant. Compare CONDITIONAL MUTANT.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005