MICROBIOLOGY LAB MIDTERM (LAB NOTEBOOK)
LATEST 2025-2026 EXAM UPDATE QUESTIONS AND
ANSWERS
The ____ mechanical stage knob moves the slide holder left to right. -
Answer-small
Parfocal means the image remains in focus after you have rotated the
_____________________ from 4x to 10x. - Answer-revolving
nosepiece
As you increase magnification from 4x to 10x to 40x, what happens to
the intensity of light that reaches your eyes? - Answer-it gets darker, you
have to make the light stronger
What part of the microscope should you use to increase the amount of
light traveling through the specimen and reaching you eye? - Answer-
iris diaphragm lever
Which objective lens requires oil immersion? - Answer-100x
Which objective lens has the greatest working distance? - Answer-10x
, Which objective lens requires setting the iris diaphragm lever almost all
the way open (to the left)? - Answer-40x
How does depth of field change as you increase magnification? -
Answer-it increases
How does depth of field change as you decrease magnification? -
Answer-it decreases
Concepts of depth of field and working distance are important to realize
when using the oil immersion (100x) objective lens which provides what
total magnification? - Answer-1000x
What is the total magnification when using the scanning lens? -
Answer-40x
What is one special advantage of using the TEM? - Answer-it is capable
of enlarging an image 1,000,000x
The TEM is used most often to look at what group of microbes? -
Answer-viruses
What are 3 advantages of using SEM over TEM? - Answer--live
specimens can be used
-more natural size and shape
-much less time for preparation
LATEST 2025-2026 EXAM UPDATE QUESTIONS AND
ANSWERS
The ____ mechanical stage knob moves the slide holder left to right. -
Answer-small
Parfocal means the image remains in focus after you have rotated the
_____________________ from 4x to 10x. - Answer-revolving
nosepiece
As you increase magnification from 4x to 10x to 40x, what happens to
the intensity of light that reaches your eyes? - Answer-it gets darker, you
have to make the light stronger
What part of the microscope should you use to increase the amount of
light traveling through the specimen and reaching you eye? - Answer-
iris diaphragm lever
Which objective lens requires oil immersion? - Answer-100x
Which objective lens has the greatest working distance? - Answer-10x
, Which objective lens requires setting the iris diaphragm lever almost all
the way open (to the left)? - Answer-40x
How does depth of field change as you increase magnification? -
Answer-it increases
How does depth of field change as you decrease magnification? -
Answer-it decreases
Concepts of depth of field and working distance are important to realize
when using the oil immersion (100x) objective lens which provides what
total magnification? - Answer-1000x
What is the total magnification when using the scanning lens? -
Answer-40x
What is one special advantage of using the TEM? - Answer-it is capable
of enlarging an image 1,000,000x
The TEM is used most often to look at what group of microbes? -
Answer-viruses
What are 3 advantages of using SEM over TEM? - Answer--live
specimens can be used
-more natural size and shape
-much less time for preparation
