Download Zoology Laboratory No. – 1- Microscope One of the most important

Zoology
Laboratory No. – 1Microscope
One of the most important instrument that will use in
biology laboratory .
The "micro " word means small , the second word " scope "
means something for looking with .
Type of microscope :
A- light ( compound ) microscope .
B –dissecting microscope .
C- flu recent microscope .
D- electronic microscope .
The compound microscope
Uses tow sets of lenses , Ocular and objective . there are
tow types of compound microscope according to number of
ocular lenses :
1- monocular microscope (one ocular lens)
2- binocular microscope ( tow ocular lens ).
Part of compound microscope :
The microscope included four system :
A- Supporting system
1- Base : the bottom portion on which the microscope rests .
2- Arm : curved part in which the microscope its carried .
3- Stage : a palate form on which slides to be studies are
placed , the opening in the center allows light to
passé from below through the object being
examined .
4- mechanical stage: an adjustor knob below the stage move
the stage forward and backward and
from side to side .
5- Stage clip : tow clips mounted on the stage that hold slides
in place .
6- Body tube : the portion that receive the ocular .
B- Illumination system
1- Light : come from a lamp that fix into the base of the
microscope .
2- Condenser : A lens located beneath the stage opining that
controls the light – beam size .
3- Diaphragm : located beneath the stage , and function to
regulated light intensity passing through the
lenses.
C- Adjustment system
1- Coarse adjustment knob : when turned ,and lower body
tube or the Stage for focusing the
microscope occurred . used with
4X and 10X.
2- Fine adjustment knob : usually found below or external the
coarse adjustment knob , and used
with high power or oil immersion
lenses for fine or final focusing .
D- Magnification system
1- Ocular lens (eye piece) : A removable lens at the tope of
the body tube , marked 10X in
most microscope .
2- Scanning objective lens : A lens marked 4X in most
microscope .
3- Lower power objective lens : A lens marked 10X in most
microscope .
4- High power objective lens: A lens marked 40X in
microscope
5- Oil – immersion objective lens : A lens marked 100X in
most microscope and distinguished by an
colored circle – oil immersion called this
because it look at the objective through a
drop of oil ( cedar – wood oil ) .
6- Nosepiece : A plate usually circular , at the bottom of the
body tube .
7- Revolving nosepiece : it is a movable part of the nosepiece
that contain the various objective lenses .
Magnification
The magnification of the microscope is calculated by
multiplying the magnification of the ocular lens by the
magnification of the objective lens.