  Gene skeptics have suggested that there is a lack of coherence in gene talk because biologists often talk as if genes code for polypeptides, but then turn around and talk about genes for RNA molecules that are not translated into polypeptides (including genes for RNA [tRNA], ribosomal RNA [rRNA], and interference RNA [iRNA]). This account shows that conceiving of genes for rRNA involves the same idea as conceiving of genes for polypeptides. In both cases, the gene is the segment of DNA, split or not, that determines the linear sequence in the molecule of interest.