Regulation of these structures is the primary function of RNA complexes formed from piwi-interacting RNA. A group of these structures that uses a mechanism similar to rolling circle replication are called helitrons. An unusually high amount of these structures are found in Trichomonas vaginalis, which also has the Mariner type of these structures. LINEs and SINEs are two classes of these structures, the latter of which includes the widespread (*) Alu element. Knockout rats are often produced with the Sleeping Beauty system of these structures. The Ac/Ds system in corn uses class 2 examples of these structures, which use a “cut-and-paste” mechanism. (-5[1])For 10 points, name these genetic sequences discovered by Barbara McClintock, (10[2])which (10[1])can move around a genome. ■END■ (10[1])