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Explain the various types of tropism in plants .

Explain the various types of tropism in plants.

Answers

Eric
1.phototropism
- Growth movements of plant shoots in response to unilateral sources of light
- The tip of the shoots produce auxins down the shoot
- Light causes auxins to migrate to outer side/darker side causing growth on the side away
from light hence growth curvature towards source of light roots are negatively
phototrophic
2.Geotropism
- Response of roots/parts of a plant to the direction of force of gravity
- Auxins grow towards the direction of force of gravity causing positive geotropism in roots
while shoot grows away from force of gravity (negatively geotrophic)
-
3.Thimotropism/Haptotropism
- Growth response of plant when in contact with an object
- Contact with support causes migration of auxins to outer side causing faster growth on the
side away from contact surface
- This causes tendrils/stem to twin around a support
-
4.Hydrotropism
- growth movement of roots in response to unilateral source of water/moisture
- the root grows towards the source of water/ positively hydrotropic while leaves are
negatively hydrotropic
-
5.chemostropism
- growth movement of parts of plant to unilateral source of chemicals
- the chemicals form a gradient between two regions e.g. pollen tube growing towards the
ovary through the style
ericmunguti answered the question on October 9, 2018 at 04:20

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