Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 25 Plant Responses and Adaptations. Set Up Foldable • Fold Long and Skinny (hotdog) • Fold short and fat 2 times (hamburger) • Open so looks like below, crease is on top What is a tropism? Tropism ~ a response of a plant to an environmental stimulus. 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) What is phototropism? Phototropism ~ a tendency of plants to grow toward a source of light. Phototropism • Phototropism is a change in the growth of a plant in response to light. • The stalk displays positive phototropism growing towards the light. What is gravitropism? Gravitropism ~ a tendency of a plant to grow in a direction in response to the force of gravity. What is thigmotropism? Thigmotropism ~ the response of plants to touch. 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. Hydrotropism • Hydrotropism is a change in the growth of a plant in response to water. • The roots display a positive hydrotropism growing towards water. Turgor Pressure • http://www.kscience.co.uk/animations/turgor.htm • Click on link above for example The cell’s vacuole does not have any water in it. The cell is flaccid. The vacuole does not have a lot of water in it. The vacuole and cell wall push against each other. The vacuole is now full of water.