Microscope is an
instrument which helps to see those things that cannot see with our naked eyes.
“Micro” means smalland “scope” means tosee.
1) Eyepiece
(ocular): where you look through to see the image
2) Body tube: Holds the
eyepiece and connects it down to the objectives
3) Fine
adjustment knob: Moves the body of the microscope up/down more slowly; fine
control. Gets the specimen exactly focused. We only use this after we first
use the coarse adjustment knob.
4) Nosepiece: Rotating
piece at the bottom of the body tube. Let’s us choose between several lenses
(objectives.)
5) High power
objective: Used for high power magnification (the longer objective lens)
6) Low power
objective: Used for low power
magnification
7) Diaphragm: Controls
amount of light going through the specimen
8)
Light/mirror: Source of light, usually found near the base of the microscope.
9) Base: Supports the
microscope
10) Coarse
adjustment knob: Moves body of the microscope up/down more quickly; Gets specimen
approximately focused.
11) Arm: Holds main
part of the microscope to the base.
12) Stage
clips: Hold the slide in place.
13) Inclination
joint: Use to tilt the microscope.
A cell is the unit of
structure and function of a living organism.
First main Difference between animals and plants cell is that the outer most
covering in plant cell is cell wall.
The second one is cell membrane
is present under the cell wall in plants. But it is the outer most covering of
the animal cell.
Cytoplasm (خلیہ مائع) is a thick
viscous(گاڑھا) liquid which fills the
space between the nucleus and the cell membrane.
Centrioles: Animal cells contain organelles
known as centrioles, which are not present in plant cells. Centrioles help move
chromosomes during cell division.
Vacuole is a sac (تھیلی) like structure which
store waste material for some time before removal from the body.
Vacuole: Animal cells may have many tiny
vacuoles.
A
plant cell usually has a single large vacuole, which serves as a
storage tank for food, water, waste products, and other materials.
Nucleus is the most
important part of the cell. It controls all activities of the cell.
Plant cell has chloroplastwhich has green pigment called chlorophyll(پودوں اور پتوں کو سبز رنگ دینے والا مادہ).It helps plants to prepare its own
food.
The largest cell is
the egg of an Ostrich.
Many organs when work
together makes a system.
Mouth, stomach, small intestine,
liver etc. work together to make digestive system.
Heart, vessels
called veins and arteries make circulatory system.
Nose, windpipe
and lungs make respiratory system(نظام تنفس).
Removal of
wastes from the body and nervous system (اعصابی نظام) for overall control of the body is calledexcretory system (نظام اخراج).
Nervous system is made up of brain,
spinal cord and nerves.
Difference between animal and plant cell.
Which instruments can help to see micro-organisms clearly…………
a) Telescope
b) Microscope
c) Hand lens
d) all of these
In microscope the lens towards the eye is called piece lens while toward the object is called……….. a) Subjective lens b) Objective lens c) Large lens d) none of these
