Someday in junior high school.
Mr. Fauzi open here class.
“Good morning students.
How are you today ?”
“Good morning sir, I’m
fine. Thank you, and you?”
“I’m fine too”
“Ok, today we
will talking about new subject. Plant movement. Anybody know, what the meaning
of plant movement ?”
“Sir” a student put her hand up.
“ yes. Solikhin,”
“ Plant movement is
movement by plant, but is different with our movement. We can move all of our
body like hands, footh, etc and we can show that, but for us, plant movement are
often make we confuse because we can show their move only with our eyes.”
“Good job. Your
answer is right enough Solikhin. Well, students, please open your e-book, page
43 chapter 9th.
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Movement is one kind of responses of an organism to stimulus. Stimulus can come
from outside (external) or from the inside (internal)of the organism on
primitive organisms,the ability to respond the stimulus is very simple which is
called as irritability.
Plant has certain sensitivity to give response to the stimulus it is
received.
Every stimulus that strikes plant will be replied by thae plant.This
response
in
from of movement from the parts of plant.
The
Various Kind of Movement in Plant
Based on its stimulus,the movements in plant are grouped into three, those
are autonomic (endogenous) movement, exogenous movement, and hygroscopic
movement.
Autonomic
(endogenous) movement
Autonomic (endogenous) movement that is not known yet its cause certainly
but predicted this motion is caused by stimulus that comes from the body of
plant itself.in other words,autonomic movement is movement that is not caused
by external stimulus.
Example:
a. the flowing movement of cytoplasm in cell.
b. The bending movement of leaf bud because of difference of growth
velocity.
c. Movement that is shown by plant when grows such as the growth of
root,stem,leaf,and flower.
d.
The rotating movement of chloroplast to encircle cell in Hydrilla sp.
Hygroscopic
Movement
Hygroscopic movement of part of plant that is caused by the influence
of
the change of water level from its cells so happens nonhomogenouse
wrinkling.
Example:
a.The breaking of dried nut fruit leucaena glauca castor Caesalipinia
pulcherrima.
b.The opening of sporangium in fern as cause of the wrinkling of annulus
cell.
Exsogenous
Movement
Exogenous movement is plant movement that is caused by external stimulus
from the plant body. The Various Kinds of Exogenous Movement in Plant:
1.
Nastic
Nastic movement is caused by stimulus. Nastic movement is separated
into five kinds, those are photonasty, nictinasty, thigmonasty,thermonasty, and
complex nasty. Nastic occurs due to the difference of turgor pressure.the
easiest example is ’’sleep’’ movement shown by many of pea family
(leguminosae). The sleep movement is called nyctinasty (nyktos= night).
1.1 Fotonasty
Photonasty is nasty movement that is caused by stimulus of sunlight.
Example:
The opening and closing of Mirabilis jalapa
at certain time when there is light.
1.2 Nictinasty
Nictinasty is nasty movement that is caused by dark condition (sleeping
movement). The leaves of leguminous plants (Leguminosaceae) will be closed at
night. The leaves will be open again in the morning. In addition to the
atmosphere caused by the dark, the motion "sleep" of leaves can occur
due to changes in turgor pressure in the leaf joints.
Example: The closing of compound leaves in Sesbania grandiflora,
Leucaena glauca, at night.
1.3 Thigmonasti
Thigmonasti is nasty movement caused by mechanical
stimulation of touch or pressure. Tigmonasti term comes from the
Greek, which means that thigma touch. Motion tigmonasti with
seismonasti called. The example: the closing of leaves of
Mimosa pudica when touched.
1.4 Thermonasty
Thermonasti is nasty movement that is caused by temperature
stimulus. For example, tulip flower will develop if suddenly gets
temperature increment and close anymore if temperature
decreases.
1.5Complex Nasty
Complex nasty is nasty movement that is caused by several factors
altogether, such as sunligt, temperature, water and chemical substance.
The example, the opening and closing of stomata.
2.
Tropisme
Tropism is the
movement of a part of plant organ in response to stimulus.the direction can be
toward or away from the stimulus. According to the kind of its stimulus,tropism
is separated into five:
a.
Phototropisme
Phototropism is
tropism movement that is caused by the stimulus of sunlight. The example,the
tip of plant that lies in room will bend to direction of incident light.
b.
Geotropism
Getropism is
tropism movement that follows Eart gravitational force. Geotropism is divided
into two, those are as follows.
- Geotropisme positif.
Positive
geotropism is geotropism movement that its direction is downward (going to
Eart). The example the tip of root grows to the direction of gravitation
- Geotropisme negatif.
Negative
geotropism is geotropism movement that its direction is upward (leaving Eart).
The example the tip of stem grows upward leaving grafitational force.
c.
Chemotropism
Chemotropism is tropism movement that is caused by
stimulus of
chemical substances. Chemotropism is separated into
two kinds,
those are as follows.
- --Positive chemotropism
Positive chemotropism is chemotropism that its
direction approaches source of stimulus. the example themovement of root to
food substance in soil.
- --Negative chemotropism
Negative chemotropism is chemotropism movement that
its direction is leaving source of stimulus.for example, movement of laves
poison.
d.
Thigmotropism.
Thigmotropism is tropism movement that is caused by
stimulus
of touch to harder thing. This movement is called
thigmotropism
(thigmo = touch). The example are Piper betle and
cucumber.
e.
Hydrotropism
Hydrotropisme is
the movement of plant root that is influenced by reservation of soil
water.commonly,root grows straightly downward,but if in this direction is not
found onough of water,then the root will grow bending to direction that has
enough of water.
3.
Taxis
Taxis is transfer
movement of all body to stimulus that its direction is determined by the
stimulus. Based on the kinds of its stimulus,taxis is separated into two
kinds,namely phototaxis and chemotaxis
a. Phototaxis
Phototaksis is taxis movement
that is caused by stimulus of sunlight. For example the movement of chlorophyll
to the surface that gets light and movement of spore that has flagella to the
light place.
b. Chemotaxis
Chemotaxis is taxis movement that is caused by chemical stimulus.for
example movement of spermatozoid(part that is formed by plant)of moss and fern
to ovum that is found in archegonium attracted to the sugar or protein that is
produced by archegonium.
Courtesy :
Youtube.com
Ida Rianawat
