TROPISM NOTES

1. TROPISM NOTES • One form of energy is mechanical – where motion happens due to energy being used. • One way to tell work is done is because the object moves a certain distance… motion. • Motion can be seen in many ways that affect our everyday life…

2. Some of these ways are: • Geotropism • Turgor Pressure • Tropism

3. Tropism • Tropism is growth in response to an external stimulus (factor that elicits a response). • Positive tropism: Plant growth toward a stimulus (water, sunlight) • Negative tropism: Plant growth away from a stimulus (spilled gas, toxins, too much sun or not enough)

4. Phototropism • Phototropism is a change in the growth of a plant in response to light. • The stalk displays positive phototropism growing towards the light.

5. Geotropism (Gravitropism) • Geotropism is a change in the growth of a plant in response to gravity. • The stalk displays a negative geotropism growing away from gravity. • The roots display a positive geotropism growing towards gravity. Negative Positive

6. Hydrotropism • Hydrotropism is a change in the growth of a plant in response to water. • The roots display a positive hydrotropism growing towards water. Positive Water