BIOL 240L LAB EXAM QUESTIONS WELL
RESOLVED AND 100%ACCURATE
PASSING SOLUTION
Transparent - answer ✔✔-Simple Stain: What colour are unstained bacterial cells under a
microscope
All the cells get stained the same colour - answer ✔✔-Simple Stain: Why is it called a simple
stain (reference colouring of the cells)
Cell morphology (size and shape) - answer ✔✔-Simple Stain: What do we learn about the cells?
Methylene blue, crystal violet, red fuschin - answer ✔✔-Simple Stain: Give some examples of
dyes used
Positive and Negative - answer ✔✔-Simple Stain: There are 2 main types of simple stains, what
are they?
alkaline (basic) - answer ✔✔-Simple Stain: In a positive stain, the stain is __________
The chromophore - answer ✔✔-Simple Stain: What gives the dye colour?
cationic (positively charged) - answer ✔✔-Simple Stain: the chromophore is ________
,Methylene blue (chloride) - answer ✔✔-Simple Stain: What was the name of the dye we used?
All of the stains would be coloured blue - answer ✔✔-Say we stained Se, Bs, and Ec with
Methylene blue
What colour(s) would they stain?
Prevent cooler, contaminated air from getting into the test tube and to sterilize the mouth of
the tube - answer ✔✔-What is the purpose of flaming the mouth of the test tube?
Coagulates the bacterial proteins and adheres them to the surface of the slide - answer ✔✔-
How does heat fixing work?
Flooding the slide with dye and washing it would just wash away the smear - answer ✔✔-What
would happen if we didn't heat-fix?
The proteins would denature and the bacterial cells would be deformed. - answer ✔✔-What
would happen in we heat fixed too much?
Lens system, Gears for adjustment, Light source - answer ✔✔-Microscope Operation: 3 main
parts
The objective lens and the ocular lens - answer ✔✔-Microscope Operation: What magnifies the
image? (2 parts)
The arm and the base - answer ✔✔-Microscope Operation: What parts should we use to carry a
microscope
, Stage all the way up, The 4X objective lens, cord wrapped - answer ✔✔-Microscope Operation:
How do we store a microscope
To move the slide up, down, left, right to observe the smear - answer ✔✔-Microscope
Operation: What is the purpose of the stage?
The part of the microscope containing the objective lenses - answer ✔✔-Microscope Operation:
what is the nosepiece
ocular lens x objective lens - answer ✔✔-Microscope Operation: How do you calculate total
magnification?
The iris diaphragm controls the amount of light that passes through the condenser - answer
✔✔-Microscope Operation: What is the relationship between the iris diaphragm and the
condenser
Contrast decreases - answer ✔✔-Microscope Operation: what happens when too much light is
passed through the slide?
match lens magnification to light setting like 100X for BOTH (put light all the way) - answer ✔✔-
Microscope Operation: How to maximize capture of your image? (lens and light settings)
FINE and COARSE adjustment knobs - answer ✔✔-Microscope Operation: What are names of
knobs we use to focus the image on the slide?
Rotate by knurled ring - answer ✔✔-Microscope Operation: Instead of rotating lenses on the
nosepiece by the lens, what should we use?
Focus AWAY from your slide/specimen - answer ✔✔-Microscopic Operation: What is the Basic
Rule of Focus?
RESOLVED AND 100%ACCURATE
PASSING SOLUTION
Transparent - answer ✔✔-Simple Stain: What colour are unstained bacterial cells under a
microscope
All the cells get stained the same colour - answer ✔✔-Simple Stain: Why is it called a simple
stain (reference colouring of the cells)
Cell morphology (size and shape) - answer ✔✔-Simple Stain: What do we learn about the cells?
Methylene blue, crystal violet, red fuschin - answer ✔✔-Simple Stain: Give some examples of
dyes used
Positive and Negative - answer ✔✔-Simple Stain: There are 2 main types of simple stains, what
are they?
alkaline (basic) - answer ✔✔-Simple Stain: In a positive stain, the stain is __________
The chromophore - answer ✔✔-Simple Stain: What gives the dye colour?
cationic (positively charged) - answer ✔✔-Simple Stain: the chromophore is ________
,Methylene blue (chloride) - answer ✔✔-Simple Stain: What was the name of the dye we used?
All of the stains would be coloured blue - answer ✔✔-Say we stained Se, Bs, and Ec with
Methylene blue
What colour(s) would they stain?
Prevent cooler, contaminated air from getting into the test tube and to sterilize the mouth of
the tube - answer ✔✔-What is the purpose of flaming the mouth of the test tube?
Coagulates the bacterial proteins and adheres them to the surface of the slide - answer ✔✔-
How does heat fixing work?
Flooding the slide with dye and washing it would just wash away the smear - answer ✔✔-What
would happen if we didn't heat-fix?
The proteins would denature and the bacterial cells would be deformed. - answer ✔✔-What
would happen in we heat fixed too much?
Lens system, Gears for adjustment, Light source - answer ✔✔-Microscope Operation: 3 main
parts
The objective lens and the ocular lens - answer ✔✔-Microscope Operation: What magnifies the
image? (2 parts)
The arm and the base - answer ✔✔-Microscope Operation: What parts should we use to carry a
microscope
, Stage all the way up, The 4X objective lens, cord wrapped - answer ✔✔-Microscope Operation:
How do we store a microscope
To move the slide up, down, left, right to observe the smear - answer ✔✔-Microscope
Operation: What is the purpose of the stage?
The part of the microscope containing the objective lenses - answer ✔✔-Microscope Operation:
what is the nosepiece
ocular lens x objective lens - answer ✔✔-Microscope Operation: How do you calculate total
magnification?
The iris diaphragm controls the amount of light that passes through the condenser - answer
✔✔-Microscope Operation: What is the relationship between the iris diaphragm and the
condenser
Contrast decreases - answer ✔✔-Microscope Operation: what happens when too much light is
passed through the slide?
match lens magnification to light setting like 100X for BOTH (put light all the way) - answer ✔✔-
Microscope Operation: How to maximize capture of your image? (lens and light settings)
FINE and COARSE adjustment knobs - answer ✔✔-Microscope Operation: What are names of
knobs we use to focus the image on the slide?
Rotate by knurled ring - answer ✔✔-Microscope Operation: Instead of rotating lenses on the
nosepiece by the lens, what should we use?
Focus AWAY from your slide/specimen - answer ✔✔-Microscopic Operation: What is the Basic
Rule of Focus?
