Topolins are aromatic examples of these compounds. The LONELY GUY gene family activates these compounds, which trigger the phosphorylation of type-B ARR (“A-R-R”) transcription factors. Isopentenyl transferase is a rate-limiting enzyme in the biosynthesis of these compounds, which can also be formed by prenylation of recycled tRNAs. These compounds bind to the histidine kinase receptor AHK4, which is disabled in CRE1 (“C-R-E-one”) Arabidopsis mutants. Skoog and Miller discovered these compounds, which include phenylurea derivatives and adenine derivatives like kinetin and zeatin. The ratio of these compounds to auxins determines whether root or shoot formation dominates. For 10 points, name these plant hormones that are named for their role in promoting cell division. ■END■