TROPISM

TROPISM DEFINITION

• How an organism reacts in a particular direction in response to external stimulus.

POSITIVE AND NEGATIVE TROPISMS

• Positive Tropisms - The plant grows in the direction from which the stimulus works.
• Negative Tropisms - The plant grows away or in the other direction from which the stimulus works.

STIMULI AND STIMULUS

• Stimuli - Is plural or more than one.
• Stimulus - Is singularly or only one.

GRAVATROPISM

• A plants movement in response to Gravity.
• Postive - Grows towards gravity.
• Negative - Grows away from Gravtiy.

CHEOTROPISM

• A plants movement in response to chemicals
• Positive - Growing more because of fertilizer.
• Negative - Grows less or dies because of weed killer.

PHOTOTROPISM

• A plants movement in response to light.
• Positive - The plants are moving to face the sun.
• Negative - When the roots grow away from the light.

THENMOTROPISM

• A plants movement in response to temperature change
• Positive - The temperature helps the plant grow.
• Negative - The temperature hurts the plant.

HYDROTROPISM

• A plants movement in response to water.
• Positive - Moves towards the water
• Negative - Moves away from the water

THISMOTROPISM

• A plants movement in response to Touch.
• Positive - Vines growing to touch a wall.
• Negative - Touch Me Nots: They close up because of touch.