coordination and response in plants- topic 9

• plants respond to stimuli, but do not have a nervous system, changes induced by stimuli are detected by changes in chemicals. response of plants slower
• geotropism, positive growth down with gravity, negative growth up against gravity. shoots curve upwards away from gravity- negative geotropism. roots curve down towards gravity- positive geotropism
• positive- towards a light source, negative- away from a light source. plant tip releases auxins, make cells elongate, auxins accumulate on dark side, forces cells to bend towards the light, leaves now absorb Max sunlight