PLANT TROPISM
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Transcript PLANT TROPISM
PLANT TROPISM
Objectives
Identify tropisms in plants.
Examine effects of tropisms in plants.
Recall differences in tropisms and effects of
tropisms in plants.
What is Tropism?
A growth movement whose
direction is determined by
the direction of the stimulus.
Tropisms cause a change in
growth pattern.
Two Types of Tropisms
1. Positive Tropism
2. Negative Tropism
Positive Tropism
Grows in the direction from
which the stimulus originates .
Growth toward
the sun.
Negative Tropisms
Growth away from the stimulus.
Growth away from
gravity.
http://www.cccmkc.edu.hk/~sbjbiology/AL%20BIO/Continuity%20of%20life%20growth%20and%20development/Growth%20and%20development_image/Tropism_image/Phototropism%20in%20
mung%20bean%20seedling.jpg
4 TYPES OF TROPISMS
Phototropism
Geotropism
Hydrotropism
Thigmotropism
PHOTOTROPISM
Response to light
GEOTROPISM or
GRAVITROPISM
Response to gravity
HYDROTROPISM
Response to water
THIGMOTROPISM
Response to touch
Summary
What is a tropism?
A growth movement towards a stimulus.
4 Types of Tropisms
Phototropism-growth toward light.
Geotropism-growth due to gravity.
Hydrotropism-growth toward water.
Thigmotropism -growth due to touch.