Tropism in Bean Plants Kai-Lou Yue, Angela Lee, Diana Zhou, Janice Huang

Gravitropism Results What is Gravitropism? Gravitropism is the turning or growth movement by a plant, fungus, or animal in response to gravity. RESULTS: no matter what position they were placed in, the beans always grew in the direction of gravity. ●In CD case, top two beans upside, the right side facing right, the left facing left, and the bottom two were facing down (same direction as gravity) ●Plant needs to compete with other plants for water and nutrients, roots pull nutrients from below, stem needs photosynthesis ●Auxin concentration higher on lower side of root, grows more on upper side, causing a bend downwards ●We expected all seeds to follow gravitropism ●out of 8 beans, only 4 showed growth ●Day 8, only one bean able to be transplanted ○root went sideways, then bent downwards to be in line with gravity’s direction

RESULTS: inconclusive because our plant was not tall enough, time not enough ●we expected plant to follow phototropism and grow towards light source, avoiding obstacles in box ●phototropism occurs because plants need sunlight to go through photosynthesis to produce energy ●auxin concentrated on shady side, causes plant to bend towards sun ●growth rate: 0.29 cm/day ○plant did not emerge from soil for week Phototropism Results What is Phototropism? Phototropism is the turning or growth movement by a plant towards a source of light.

Summary In conclusion, our plant experienced gravitropism but did not have enough time to provide results for phototropism. In the CD case, the roots of the seeds bent in the direction of gravity. Our plant was too short to display the effects of phototropism.