【单选题】Although spliceosomal introns seem to be limited to eukaryotes, the other three intron classes are not. Genes with group I and II introns have now been found in both bacteria and bacterial viruses. Ba...
【单选题】As many as ______ of miRNA genes may lie in the introns or even exons of other genes. These are usually, though not exclusively, found in a sense orientation, and thus usually are regulated together w...