Hi my name is Emily, and I'm doing a project on the different plant tropisms. Tropisms are responses by plants due to a negative or positive outside stimulus. Let's take a look at the different tropisms that are involved with a plant!
Emily: Phototropism is a response by plants that involves them growing towards are sometimes growing away from a light source. In this example the flower is bending towards the sun, the sun being the stimulus.
Emily: Gravitropism is a response by plants that involves the roots or shoots growing based on the force of gravity. When they are growing away from gravity it is known as negative gravitropism and growing towards is known as positive gravitropism.
Root grows towards gravity.
Shoot grows away from gravity.
Emily introduces herself and the purpose of her project: tropisms.
Emily: Hydrotropism is the movement of plants pertaining to water. The water is the stimulus, and the plant can decide if it would like to move towards the water, or away from it. In the example the roots are purposely growing towards the water source.
Phototropism
Emily: Thigmotropism is the response of plants to touch. It can either be positive or negative, but it results in the plant turning or bending from the stimulus.
Emily: In this case, the stick is the stimulus which the plant is using to keep itself upright. This is a positive thigmotropism.
Gravitropism
Now we know all about the four different plant tropisms! I'm definitely getting an A+ on this project!!