Stimulus and response in living organism
🔷️What is Stimulus?
📚Key concept:-
- A Stimulus is any change in the environment (internal and external) that causes a living organism to react against it.
- It can be light, sound, touch, temperature, smell, pain etc.
Example:- Touching a hot object or listening to a loud sound.
🔷️Response to stimulus
📚Key concept:-
- The reaction or action shown by an organism after deducting a Stimulus by an organism called a response
- It helps organism to protect themselves and adjust to their surroundings.
- It is also an defining characteristics features of living organism, because it involves the coordinate action of the nervous system(brain, spinal cord, nerves) and sense Organs (eyes, ears, skin).
Example:- Quickly pulling your hand back after Touching something hot.
Lets understand the basic differences of response in plants and animals:-
| Plants | Animals |
| Slow and gradual response | Quick and immediate response |
| Limited or no movement | Active movement |
| Hormone only | Hormone + nervous system . |
| Bending towards light (Phototropism) | Pulling hands from hot object. |
📌Real life example:- Touching a hot object:-
When you feel heat from the hot object you instantly pull your hand away.
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