Plant movements are mainly
divided in two parts –
1.Movements of Locomotion
2.Movements of Curvature
1. Movements of Locomotion – In this type of movement
Plant’s whole body or a part of plant goes from one place to another. In short
plant changes its position, is called movements of locomotion.
This type of movements is also divided in two types –
I. Autonomous Movements – This type of movements is
induced by internal stimuli. It is divided in 3 parts –
A. Amoeboid - e.g. Gametes of Spirogyra
B. Ciliary - e.g. Gametes of Chlamydomonas
C. Cyclosis –
a. Rotation –
When protoplasm moves around the central vacuole.
e.g.
Hydrilla, Vallisneria
b.
Circulation – When protoplasm moves randomly in cell.
e.g.
Tradescantia
II. Induced or Para tonic Movements – It is induced
by External stimuli. It is also divided in 3 types –
A. Chemo-tactic – e.g. Anthaloziades
B. Photo-tactic – e.g. Eye spot in algae
C. Thermo-tactic – e.g. Euglena, Chlamydomonas
2. Movements of Curvature – In this type of movement
plant shows movement without changing its position. It is divided in 2 types –
I. Autonomous Movements – Induced by internal
Stimuli.
e.g. – Desmodium gyrens (Indian Telegraph Plant)
* Epinasty & Hyponasty movements of leaves or flowers.
Epinasty – growth of upper surface of leaf/flower.
Hyponasty – growth of lower surface of leaf/flower.
II. Induced or Para tonic Movements – It is induced
by external stimuli.
Types of Induced movements –
A. Tropic Movements – It is unidirectional movement.
a. Chemo-tropic – movement
because of chemical.
e.g. Movement of pollen tube
b. Thigmo-tropic – movement
because of touch.
e.g. movement of suckers &
hairs of plant
c. Geotropic – movement
because of gravitation.
e.g. Root (+), Shoot (-)
d. Phototropic – movement
because of light.
e.g. Shoot (+), Root (-)
e. Hydrotropic – movement
because of water.
e.g. Root (+), Shoot (-)
f. Trauma-tropic – movement
because of loss or wound.
B. Nastic Movements –
a. Seism nasty – movements
because of turgor pressure or K+ ions.
e.g. Mimosa pudica
b. Thigmonasty – movements
because of touch.
e.g. movements of sensors of
pitcher plant
c. Chemo-nasty – movements
because of chemical.
e.g. pitcher plant
d. Nyctinasty – movements
because of day & night.
e.g. movements of leaves and
flowers
Comments
Post a Comment