Germination of a seed of the broad bean, Vicia faba, with half of the pot removed to show the development of the roots & shoot, which would normally be hidden beneath the soil. The main root is the first to break through the seed coat, guided downward in the soil by special gravity- sensitive cells in the root cap. Lateral roots develop later from the main root. The stem grows upward toward the light with the leaves tightly folded to protect them from damage. Once above ground, the leaves unfold.