STIMULUS& RESPONSE

STIMULIS

• A stimulus is any change in an organisms environment.
• It will cause the organism to react.
• Example: an animal is cold so it moves into the sun.

RESPONSE

• How the organism reacts to a stimulus.
• Results in a change in behavior.
• Example: getting a drink when you are thirsty.

INTERNAL STIMULUS

• Comes from inside an organism.
• Example: a person feels hot so you breath hard.

EXTERNAL STIMULUS

• Comes from outside and organism.
• Example: a person feels hot so it goes in the shade.

A PLANTS RESPONSE TO A STIMULUS

• That is called tropism.

3 TYPES OF TROPISMS FOR PLANTS

• Phototropism
• Heliotropism
• Photoperiodism

PHOTOTROPISM

HELIOTROPISM

PHOTOPERIODISM