NEET BIOLOGY

Detailed explanation-1: -In physiology, a stimulus is a detectable change in the physical or chemical structure of an organism’s internal or external environment. The ability of an organism or organ to detect external stimuli, so that an appropriate reaction can be made, is called sensitivity (excitability).

Detailed explanation-2: -Answer and Explanation: A change in an organism’s environment that causes the organism to react is called a stimulus.

Detailed explanation-3: -A change in an organism’s surroundings that causes the organism to react is called a stimulus (plural stimuli). An organism reacts to a stimulus with a response-an action or change in behavior. Another example is if you are cold, you shiver. The cold is the stimulus while the shivering is the response.

Detailed explanation-4: -Response: how the organism reacts to a stimulus and results in a change in behavior. (It is a fancy way of saying “effect”.) Example: Getting a drink when you are thirsty.

Detailed explanation-5: -For example, a child who loves playing video games generally responds by playing (response 1) when is presented with the stimulus of a video game in front of him.