what is stimulus in biology class 10

A stimulus in Class 10 biology is any change in the environment (inside or outside the body) that produces a response in a living organism.

Simple definition for Class 10

• A stimulus is a detectable change in the surroundings of an organism that makes it react.

• This change can be physical (like light, sound, touch, temperature) or chemical (like smell, taste, hormones, etc.).

• The reaction shown by the organism to a stimulus is called a response.

In textbook-style words (Class 10 level)

Stimulus: Any change in the internal or external environment of an organism that can be detected and produces a response.

Types of stimulus (useful for Class 10 answers)

• External stimulus : Comes from outside the body, like light, sound, touch, temperature, smell.

• Internal stimulus : Comes from inside the body, like hunger, thirst, pain, low oxygen, hormone changes.

Examples you can write in exams

• Sunlight acts as a stimulus for plants, so they bend towards light (phototropism).

• High temperature is a stimulus that causes sweating in humans to cool the body.

• Feeling thirsty (internal stimulus) makes you drink water (response).

• Touching a hot object (external stimulus) makes you quickly pull your hand back (response). This is a reflex action example.

One line exam-ready answer

You can safely write in Class 10:

“A stimulus is any change in the internal or external environment of an organism that can be detected and causes a response.”

Information gathered from public forums or data available on the internet and portrayed here.