Page 78 - Science Class 06
P. 78
Cells are too small to look with naked eyes.
They can be seen under a magnifying glass
Observa on of animal cells under a
or a microscope.
microscope.
Some organisms are made up of a single cell
so they are called unicellular organisms Take your fingers to your cheek from
such as amoeba, paramecium, yeast, inside your mouth and take out a small
bacterium, etc. covering carefully. Place it on a glass slide
and put a drop of iodine solu on on it.
Some organisms are made up of many cells, Now, take it under a microscope. You will
so they are called mul cellular organisms observe the structure of the animal cells
such as man, cow, rat, caterpillar, mango which are slightly different from that of
tree, rose plant, etc. the cells of a onion peel.
The egg of an ostrich is the largest single
cell.
Observa on of a plant cell under a
microscope.
Take a small piece of onion and detach a
thin layer from it. Place this thin layer of Movement and Response to S muli
the onion on a slide and put a drop of Most living things are capable of moving on
iodine on it. Take it under a microscope. their own. Animals move from place to
You will see a small chamber like place in search of food and water, to escape
structure. These are the cell of the onion. from danger and for various other reasons.
Plants do not move on their own. However,
they exhibit movement of certain parts,
such as leaves and roots, in response to
changes in their immediate environment.
A change in the immediate environment of
an organism, which produces a change in
the ac vi es of the organism, is called a
s mulus (plural: s muli). An organism’s
reac on to a s mulus is called a response.
Leaves of touch-me-not (lajwan ) curl up
when touched. Here, touch is the s mulus
and curling up of leaves is the response.
78 Science-6
