Plant responses and movements by aram omer sorkan

Prepared by Aram Omer Sorkan amp Karzan Sdiq

Salih

Plant Responses amp Movments

University of Sulamani

School of Science

Department of Biology

Purposes In this presentation we want to describe the Responses and Movements of the plant

Describe tropisms as Plant Response Describe Nastic Movements as Plant Movement

Plant ResponseTropism A tropism is a biological phenomenon indicating growth or turning movement of a

biological organism usually a plant in response to an environmental stimulus

OR The responses of plants to their environment

OR a plants directional growth response to a physical stimulus

Types of Tropism

1Phototropism

2Gravitropism

3Thigmotropism

4Chemotropism

5Hydrotropism

6Thermotropism

1Phototropism

Phototropism is the growth response of a plant in response to light direction

Positive Phototropism Vs Negative Phototropism

2Gravitropism

Geotropism is the growth response of a plant in response to gravity

Positive Geotropism Vs Negative Geotropism

Thigmotropism is the growth response of a plant to physical contact (touch)

Positive Thigmotropism Vs Negative Thigmotropism

3Thigmotropism

4Chemotropism

Chemotropism is the growth response of a plant to a particular chemical Roots

grow toward useful minerals in the soil but away from acids

Positive Chemotropism Vs Negative Chemotropism

5Hydrotropism

Hydrotropism is the growth response of a plant to water

Roots exhibit Positive Hydrotropism

6Thermotropism

Thermotropism is the movement of plant or their parts in response to changes in the

external stimulus of temperature

ExampleRhododendronCold temperature

Hot temperature

NASTIC MOVEMENTS

The non-directional movements of the plant in response to external stimuli are

called nastic movement

The direction of the movement is determined by the structure of the plant organ

itself It is not determined by an external stimulus

Types of nastic movements

1-Nyctinasty or Nyctinastic (sleep movements)

a Photonasty

b Thermonasty

c Epinasty amp Hyponasty

2-Seismonastic movements

3-Haptonastic or Thigmonastic movements

NASTIC MOVEMENTS

1-Nyctinasty Movement This is induced by diurnal variations in light and temperatureThe diurnal movements

PhotonastyThe principle stimulus of Photonasty is the photoperiod

Day Night

ExampleOxalis triangularis (Shamrock flower)

Photonasty

1-Nyctinasty Movement

Example Cestrum nocturnum (Night Jasmine)

Day Night

ThermonastyIt takes place due to temperature changes

1-Nyctinasty Movement

Example Tulipa clusiana (Tulip flower)

Rise Temperature Low Temperature

1-Nyctinasty Movement

Epinasty Vs Hyponasty

Epinasty Hyponasty

2-Seismonastic movements

The shock movement

Movement in plants in response to touch as well

as other forms of physical contact or mechanical

disturbance such as shaking wounding wind

raindrops and intense heat or burning

In the case of the sensitive plant (Mimosa pudica)

a leaflet leaf or group of leaves rapidly folds

and bends in response to the external stimulus

3-Haptonastic Movement

Haptonastic occurs due to stimulus of touch

plant movement in response to touch or physical contact without regard to thedirection of the stimulus Thigmonastic movements are exemplified by the closing ofthe insect-eating plant Venusrsquos flytrap (Dionaea muscipula) and the bending of theglandular hairs of sundew (Drosera sp) as a result of contact with an insect

Sundew Venusrsquos FlytrapCarnivorous Plant

References

httpbiologyboomcomnastic-movements

httpwwwpreservearticlescom2011121918563different-types-of-nastic-

movements-movement-plantshtml

httpwwwcropsreviewcomplant-movementshtml

MOORE R CLARK WD VODOPICH DS 2003 Botany 2nd ed New York NY

McGraw-Hill p 443-454

httpleavingbionetplant20responseshtm

Thank YouhellipAny Question

Any Question Any Question