tropism,types of tropism,photosynthesis,photosynthesis in plants,neccessary activities for photosynthesis,transpiration,points to remember of photosynthesis,plant physiology,tropism in plants

1. PLANT
PHYSIOLOGY

2. CONTENT
INTRODUCTION
TROPISM IN PLANTS
NASTIC MOVEMENTS
PHOTOSYSNTHESIS
TRANSPIRATION
POINTS TO REMEMBER
GLOSSARY
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3. Hello!
I am R.VISHNU PRIYA
D.t.ed,b.sc,b.ed.
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4. INTRODUCTION
Have you observed the leaves of Mimosa
Pudica (touch-me-not plant) closes on
touching,wheres Helianthus annus
(sunflower) follows the path of the sun.
Plants are sensitive to external factors
like light,gravity, temperature etc.

5. TROPISM IN PLANTS
▪ TROPISM is a unidirectional movement of a whole or
part of a plant towards the direction of stimuli.
▪ TYPES OF TROPISM :
▪ Phototropism
▪ Geotropism
▪ Hydrotropism
▪ Thigmotropism
▪ Chemotropism 5

6. • Phototropism: movement of a plant part towards
light.e.g.shoot of a plant.
• Geotropism: Movement of a plant in response to
gravity.e.g.root of a plant.
• Hydrotropism: Movement of a plant or part of a plant
towards water. E.g. root of a plant.
• Thigmotropism : Movement of a plant part due to
touch. e.g.climbing vines. 6
DEFINITION FOR TYPES OF TROPISM

7. ▪ Chemo tropism: Movement of a part of plant in
response to chemicals.e.g.growth of a pollen tube
in response to sugar present on the stigma.
▪ Tropism is generally termed positive if growth is
towards the signal and negative if it is away
from the signal.
▪ The shoots are positively phototropic.
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8. Do you
know ?
Some halophytes produce
negatively geotropic
roots(e.g.Rhizophora).
These roots turn 180 degree
upright for respiration. 8
RHIZOPHORA

9. NASTIC MOVEMENTS
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▪ NASTIC MOVEMENT orS are non-directional response of a plant or
part of a plant to stimulus.
▪ Classification:
Photonasty: movement of a part of a plant in response to
light. E.g Ipomea alba.
Thigmonasty: movement of a part of plant in response to touch.
its also known as seismonasty.e.g. Mimosa pudica.
Thermonasty : movement of part of a a plant is associated with
change in temperature.e.g. tulip.

10. 10
photonasty
Thermonasty
Thigmonasty

11. • PHOTO means LIGHT and SYNTHESIS
means TO BUILD.
• PHOSYNTHESIS: building up with the
help of light.
• During this process, light energy is
converted into chemical energy.
• Green plants are autotropic,because
they prepare their food materials
through the process called
photosynthesis. 11
PHOTOSYNTHESIS

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13. Necessary activities for photosynthesis
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Plants
chlorophyll
water
Carbon dioxide
Sun light

14. TRANSPIRATION
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The loss of water in the form of water
vapour from the aerial parts of the plant
body is called as transpiration.
The leaves have tiny, microscopic pores
called stomata.
Each stomata is surrounded by guard
cells.
These guard cells help in regulating the
rate of transpiration by opening and
closing of stomata.

15. POINTS TO REMEMBER
Growth movement whose direction is determined
bythe direction of the stimulus is called tropism.
Non-directional, response of a plant part to stimulas
is called nastic movement.
The process by which plants prepare their food
material is called photosynthesis.
The loss of water in the form of water vapour from
the aerial parts of the plant body is called
transpiration.
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