2.79 Plants and stimuli

- stimuli is the changes in the environment such as temperature and light.
- plants can detect the changes in the environment through their receptors.
- response to stimuli detected by the receptors often is growth. response in growth is called tropism.
- examples of tropisms include
tropism that involves light :: phototropism
tropism that involves gravity :: geotropism
- connection between the receptor and response usually takes the form of plant hormones which are sometimes called plant growth regulators. (an example: Auxim)