Presentation on theme: "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,"— Presentation transcript:
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.