The document discusses how plants use electrical and chemical means to communicate between cells, unlike animals which use specialized tissue. It describes how plant cells change shape through water content and how some plants like peas climb using tendrils. Tendrils curl around objects by growing at different rates on contact versus away from contact. Plants generally respond slowly to stimuli by directional growth, but the sensitive plant reacts very quickly to touch. Both slow and fast controlled movements in plants are possible. Chemical communication is more common than electrical between multicellular organism cells. Plant hormones help coordinate growth and environmental responses by being synthesized away and diffusing to the area of action.

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3. The sensitive plant

7. The plants use electrical-chemical means
The plants use electrical-chemical means
to convey the information from cell to cell.
to convey the information from cell to cell.
But unlike in animals, there is no
But unlike in animals, there is no
specialised tissue in plants for the
specialised tissue in plants for the
conduction of information.
conduction of information.
Plant cells change shape by changing the
Plant cells change shape by changing the
amount of water in them
amount of water in them

9. Some plants like the pea plant
Some plants like the pea plant
climb up other plants or fences by
climb up other plants or fences by
means of tendrils.
means of tendrils.
When they come in contact with any
When they come in contact with any
support, the part of the tendril in
support, the part of the tendril in
contact with the object does not grow
contact with the object does not grow
as rapidly as the part of the tendril
as rapidly as the part of the tendril
away from the object.
away from the object.

10. This causes the tendril to circle around
This causes the tendril to circle around
the object and thus cling to it. More
the object and thus cling to it. More
commonly, plants respond to stimuli slowly
commonly, plants respond to stimuli slowly
by growing in a particular direction.
by growing in a particular direction.
Because this growth is directional, it
Because this growth is directional, it
appears as if the plant is moving.
appears as if the plant is moving.
The movement of the sensitive plant in
The movement of the sensitive plant in
response to touch is very quick.
response to touch is very quick.
So controlled movements can be either slow
So controlled movements can be either slow
or fast.
or fast.

11. Firstly, they will reach only those cells
Firstly, they will reach only those cells
that are connected by nervous tissue, not
that are connected by nervous tissue, not
each and every cell in the animal body.
each and every cell in the animal body.
cells cannot continually create and
cells cannot continually create and
transmit electrical impulses.
transmit electrical impulses.
It is thus no wonder that most
It is thus no wonder that most
multicellular organisms use another means
multicellular organisms use another means
of communication between cells, namely,
of communication between cells, namely,
chemical communication.
chemical communication.

12.  Different plant hormones help to
 Different plant hormones help to
coordinate growth, development
coordinate growth, development
and responses to the environment.
and responses to the environment.
 They are synthesised at places
 They are synthesised at places
away from where they act and
away from where they act and
simply diffuse to the area of action.
simply diffuse to the area of action.

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