MICROBIOLOGY LAB PRACTICAL 1 LATEST
EXAM 2025 WITH MULTIPLE CHOICE OF
QUESTIONS AND DETAILED CORRECT
ANSWERS ALREADY GRADED A+ AND 100%
GUARANTEE PASS (BRAND NEW!!!!!)
If using 100x or oil immersion lens - CORRECT ANSWER-click the 10x
lens out of position, and place a drop of immersion oil directly
on top of the light spot on the slide.
l. Without moving the stage, click the oil lens into position
(make sure not to drag the 40x lens through the oil).
m. Look through oculars and increase light intensity by opening
the iris diaphragm in the condenser and/or turning up the
voltage regulator.
n. If necessary use fine focus to get the sharpest image
Know the proper procedure for focusing the microscope. -
CORRECT ANSWER-a. Using coarse adjustment knob in order to
bring specimen into focus and raise the stage into focus.
b. While looking through the ocular lenses, bring object into
focus using fine adjustment knob (do not adjust the coarse
adjustment knob).
,Understand the value and proper use of the fine adjustment
knob, for example, the order of the colored crossed threads
viewed at 40X. - CORRECT ANSWER-
Know the pitfalls of using the High-dry lens (40X). E.g. Do you
use the coarse focus knob when the 40X is in position? - CORRECT
ANSWER-You do not use the coarse adjustment knob. It is very
sensitive, and oil should never be used on this lens (why it is
called a high-dry). It must always be properly cleaned before
use of it.
Immersion oil - what is its function? Do you use the coarse
focus knob when the 100X is in position? - CORRECT ANSWER-a. Oil
is necessary to help reduce the refraction of light, which
increases the amount of light going to the specimen. It
increases the resolving power
b. You do not use the coarse focus knob when the 100x is in
position
Proper use of oil immersion and how to avoid problems
associated with it use. E.g. How to avoid getting oil on the 40X?
- CORRECT ANSWER-a. Take care to turn the lens turret in the
direction that will not drag the 40x lens through the oil (move
from 10x, to 4x, then to 100x).
When using oil:
c. Open the diaphragm as much as possible.
e. If the oil appears cloudy, it should be discarded.
Know how to determine total magnification of objectives +
ocular lens. - CORRECT ANSWER-a. Total magnification of the final
, image is a product of the separate magnifying powers of the two
lenses.
b. Total magnification= objective power x ocular power
c. Find objective lens power (4x, 10x, 40x, 100x) on the lens
itself. The ocular lens power we use on our microscopes is 10x.
You then multiply these two powers to get the total
magnification.
Know at least two ways to adjust light intensity on the
microscope and the order you should adjust them. - CORRECT
ANSWER-a. Use the iris diaphragm lever on the condenser or the
iris diaphragm ring on the illuminator
b. Use the light intensity knob
Iris diaphragm lever on the (sub-stage) condenser vs. the iris
diaphragm ring on the illuminator. - CORRECT ANSWER-a. Iris
diaphragm lever on the (sub-stage) condenser- a part of the
condenser which is attached to the bottom of the mechanical
stage; opens and closes the condenser, thus regulating the
amount of light shining through the condenser onto the
specimen; controls light intensity
b. Iris diaphragm ring on the illuminator- portion that is
attached to the bottom of the microscope;
Light effect on contrast and how to adjust the iris diaphragm
lever to get the best contrast. - CORRECT ANSWER-a. The iris
diaphragm's lever maximizes contrast by properly channeling
the light rays passing through to the specimen.
b. Closing the iris diaphragm, decreases the brightness and
increases the contrast.
EXAM 2025 WITH MULTIPLE CHOICE OF
QUESTIONS AND DETAILED CORRECT
ANSWERS ALREADY GRADED A+ AND 100%
GUARANTEE PASS (BRAND NEW!!!!!)
If using 100x or oil immersion lens - CORRECT ANSWER-click the 10x
lens out of position, and place a drop of immersion oil directly
on top of the light spot on the slide.
l. Without moving the stage, click the oil lens into position
(make sure not to drag the 40x lens through the oil).
m. Look through oculars and increase light intensity by opening
the iris diaphragm in the condenser and/or turning up the
voltage regulator.
n. If necessary use fine focus to get the sharpest image
Know the proper procedure for focusing the microscope. -
CORRECT ANSWER-a. Using coarse adjustment knob in order to
bring specimen into focus and raise the stage into focus.
b. While looking through the ocular lenses, bring object into
focus using fine adjustment knob (do not adjust the coarse
adjustment knob).
,Understand the value and proper use of the fine adjustment
knob, for example, the order of the colored crossed threads
viewed at 40X. - CORRECT ANSWER-
Know the pitfalls of using the High-dry lens (40X). E.g. Do you
use the coarse focus knob when the 40X is in position? - CORRECT
ANSWER-You do not use the coarse adjustment knob. It is very
sensitive, and oil should never be used on this lens (why it is
called a high-dry). It must always be properly cleaned before
use of it.
Immersion oil - what is its function? Do you use the coarse
focus knob when the 100X is in position? - CORRECT ANSWER-a. Oil
is necessary to help reduce the refraction of light, which
increases the amount of light going to the specimen. It
increases the resolving power
b. You do not use the coarse focus knob when the 100x is in
position
Proper use of oil immersion and how to avoid problems
associated with it use. E.g. How to avoid getting oil on the 40X?
- CORRECT ANSWER-a. Take care to turn the lens turret in the
direction that will not drag the 40x lens through the oil (move
from 10x, to 4x, then to 100x).
When using oil:
c. Open the diaphragm as much as possible.
e. If the oil appears cloudy, it should be discarded.
Know how to determine total magnification of objectives +
ocular lens. - CORRECT ANSWER-a. Total magnification of the final
, image is a product of the separate magnifying powers of the two
lenses.
b. Total magnification= objective power x ocular power
c. Find objective lens power (4x, 10x, 40x, 100x) on the lens
itself. The ocular lens power we use on our microscopes is 10x.
You then multiply these two powers to get the total
magnification.
Know at least two ways to adjust light intensity on the
microscope and the order you should adjust them. - CORRECT
ANSWER-a. Use the iris diaphragm lever on the condenser or the
iris diaphragm ring on the illuminator
b. Use the light intensity knob
Iris diaphragm lever on the (sub-stage) condenser vs. the iris
diaphragm ring on the illuminator. - CORRECT ANSWER-a. Iris
diaphragm lever on the (sub-stage) condenser- a part of the
condenser which is attached to the bottom of the mechanical
stage; opens and closes the condenser, thus regulating the
amount of light shining through the condenser onto the
specimen; controls light intensity
b. Iris diaphragm ring on the illuminator- portion that is
attached to the bottom of the microscope;
Light effect on contrast and how to adjust the iris diaphragm
lever to get the best contrast. - CORRECT ANSWER-a. The iris
diaphragm's lever maximizes contrast by properly channeling
the light rays passing through to the specimen.
b. Closing the iris diaphragm, decreases the brightness and
increases the contrast.
