1. Plant Tropisms

2. TROPISM
is a biological phenomenon, indicating growth or turning movement of a plant in response to an environmental stimulus

3. Tropism Types

4. Phototropism
Movement of plants toward light to maximize amount of sun for photosynthesis to make their food. Heliotropism

5. Gravitropism Movement of plants in response to gravity
Positive is toward gravity (roots)
Negative is away from gravity (shoot: stems and leaves)

6. Hydrotropism Movement by plants toward water.
Seen in roots “searching” and growing toward water which is needed for photosynthesis and to support cell structure.

8. Thigmotropism Plants moving in response to touch.
Seen in vine plants as they wrap around other plants or structures to support leaves as they grow higher and higher to reach the sun to make more food (photosynthesis).