β˜€οΈ Survival and response (AQA)

One particularly obvious category of response to the environment in organisms is movement. This is one of the most fundamental ways for a plant or an animal to enhance survival. It’s no wonder then, that much of this response is solidly built-in and automated, like a reflex.

 

There are 3 main examples of response: tropism, taxis and kinesis and reflex.

 

1. Tropism – think of a sunflower following the sun

 

 

The direct stimuli which contribute to plant survival (such as light, nutrients, gravity) are responded to by positive or negative tropisms. Tropisms get their names based on the stimulus they refer to. For example, a plant responding towards light would exhibit a positive phototropism.

 

Most plants also exhibit negative gravitropism which means they grow away from…