Phytohormones are the chemicals which regulate the growth of the plants and their functioning. The phytohormones include Auxins and Cytokinins. Auxins regulates Cell Elongation, Auxin moves to the darker side of the plant, causing the cells there to grow larger than corresponding cells on the lighter side of the plant whereas Cytokinins are a class of plant growth substances that promote cell division, or cytokinesis, in plant roots and shoots.