BSC 2011L (Bio 2 Lab) Midterm | University of South
Florida | UPDATED Questions with 100% Verified
Answers
Q1: What are the steps of the scientific method?
A: 1. Make an observation
2. Form a question
3. Form a hypothesis
4. Perform an experiment
5. Analyze the data and draw conclusions
Q2: What are the 2 kinds of light microscopes?
A: Dissecting and compound
Q3: What are the 2 light sources on a dissecting microscope?
A: Transmitting light (stage light)
Incident light (top light)
Q4: What are the microscope lenses close to your eye called?
A: Ocular lenses
Q5: What magnification are the ocular lenses?
A: 10x
Q6: What are the lenses close to the specimen called?
A: Objective lenses
Q7: What are the magnifications of the objective lenses on a
compound light microscope?
A: 4x, 10x, 40x, 100x
Q8: Why does the 100x lens need immersion oil?
A: To fill the air space between the specimen and the objective to gather enough image
forming light to produce a clearer view of the specimen
Q9: What is the name of the part that rotates the objective lenses?
A: Nosepiece
Q10: What are the 2 focus knobs called? What magnifications do
you use both of them?
,A: Coarse adjustment and fine adjustment
Use coarse adjustment on 4x and 10x
Use fine adjustment on 40x and 100x
Q11: What is the name of the part that you put your specimen on?
A: The stage
Q12: What adjusts the amount of light that passes through the
specimen?
A: Iris diaphragm and dimmer switch
Q13: How do you clean a microscope?
A: 1. Wet a piece of lens paper with lens cleaning solution
2. Gently rub the ocular lenses with the wet paper
3. Repeat step 2 using an area of dry lens paper
4. Repeat 2 and 3 for the upper condenser lens and the oil immersion objective lens
(100x)
5. Don't use anything other that lens paper to clean the glass parts or else you'll scratch
the lenses
Q14: How should the dimmer switch and stage be set up when first
operating a microscope?
A: Dimmer switch should be on lowest setting, then light intensity should be increased
until white light is emitted
Stage should be lowered all the way
Q15: How should you adjust the stage and light intensity after the
specimen is in place?
A: Move the stage all the way up with the coarse adjustment knob ,then focus on the
object by moving it away from the objective lenses
Reduce the light intensity by closing the iris diaphragm
Q16: What does parfocality mean?
A: The image stays nearly in focus when changing the magnification
Q17: Which microscope is parfocal? Which is not?
A: Compound is parfocal
Dissecting is not
Q18: How do you use immersion oil and the oil immersion lens?
A: 1. Rotate the nosepiece so it's halfway between the 40x and 100x lenses
2. Place a single, small drop of oil on the slide and carefully rotate the oil immersion lens
into it
, Q19: How should you adjust the dimmer, nosepiece, and stage
when putting away the microscope?
A: Dimmer should be on lowest setting
Nosepiece should be on lowest objective
Stage should be lowered
Q20: What are the steps of aseptic technique?
A: 1. Wash your hands
2. Clean the lab benches
3. Put on gloves
4. Put on goggles, if needed
Q21: What are the aseptic steps when using an inoculating loop?
A: Tie back hair
Wave the loop through a flame from a bunsen burner for a few seconds
Wait for the loop to cool down before touching it to an agar surface
Q22: What 2 domains are prokaryotes under?
A: Archaea and bacteria
Q23: Which is the most common of the prokaryotes? Bacteria or
archaea?
A: Bacteria
Q24: What are all cell walls of bacteria composed of?
A: Peptidoglycan and an inner plasma membrane
Q25: What staining technique can be used to determine the nature
of bacterial cell walls?
A: Gram stain
Q26: What do Gram negative bacteria look like?
A: Thin peptidoglycan layer with an outer membrane
Q27: What do Gram positive bacteria look like?
A: Thick peptidoglycan layer with no outer membrane
Q28: What color will a Gram positive bacteria stain? Why
A: Purple
Has a thick cell wall with no outer membrane
Florida | UPDATED Questions with 100% Verified
Answers
Q1: What are the steps of the scientific method?
A: 1. Make an observation
2. Form a question
3. Form a hypothesis
4. Perform an experiment
5. Analyze the data and draw conclusions
Q2: What are the 2 kinds of light microscopes?
A: Dissecting and compound
Q3: What are the 2 light sources on a dissecting microscope?
A: Transmitting light (stage light)
Incident light (top light)
Q4: What are the microscope lenses close to your eye called?
A: Ocular lenses
Q5: What magnification are the ocular lenses?
A: 10x
Q6: What are the lenses close to the specimen called?
A: Objective lenses
Q7: What are the magnifications of the objective lenses on a
compound light microscope?
A: 4x, 10x, 40x, 100x
Q8: Why does the 100x lens need immersion oil?
A: To fill the air space between the specimen and the objective to gather enough image
forming light to produce a clearer view of the specimen
Q9: What is the name of the part that rotates the objective lenses?
A: Nosepiece
Q10: What are the 2 focus knobs called? What magnifications do
you use both of them?
,A: Coarse adjustment and fine adjustment
Use coarse adjustment on 4x and 10x
Use fine adjustment on 40x and 100x
Q11: What is the name of the part that you put your specimen on?
A: The stage
Q12: What adjusts the amount of light that passes through the
specimen?
A: Iris diaphragm and dimmer switch
Q13: How do you clean a microscope?
A: 1. Wet a piece of lens paper with lens cleaning solution
2. Gently rub the ocular lenses with the wet paper
3. Repeat step 2 using an area of dry lens paper
4. Repeat 2 and 3 for the upper condenser lens and the oil immersion objective lens
(100x)
5. Don't use anything other that lens paper to clean the glass parts or else you'll scratch
the lenses
Q14: How should the dimmer switch and stage be set up when first
operating a microscope?
A: Dimmer switch should be on lowest setting, then light intensity should be increased
until white light is emitted
Stage should be lowered all the way
Q15: How should you adjust the stage and light intensity after the
specimen is in place?
A: Move the stage all the way up with the coarse adjustment knob ,then focus on the
object by moving it away from the objective lenses
Reduce the light intensity by closing the iris diaphragm
Q16: What does parfocality mean?
A: The image stays nearly in focus when changing the magnification
Q17: Which microscope is parfocal? Which is not?
A: Compound is parfocal
Dissecting is not
Q18: How do you use immersion oil and the oil immersion lens?
A: 1. Rotate the nosepiece so it's halfway between the 40x and 100x lenses
2. Place a single, small drop of oil on the slide and carefully rotate the oil immersion lens
into it
, Q19: How should you adjust the dimmer, nosepiece, and stage
when putting away the microscope?
A: Dimmer should be on lowest setting
Nosepiece should be on lowest objective
Stage should be lowered
Q20: What are the steps of aseptic technique?
A: 1. Wash your hands
2. Clean the lab benches
3. Put on gloves
4. Put on goggles, if needed
Q21: What are the aseptic steps when using an inoculating loop?
A: Tie back hair
Wave the loop through a flame from a bunsen burner for a few seconds
Wait for the loop to cool down before touching it to an agar surface
Q22: What 2 domains are prokaryotes under?
A: Archaea and bacteria
Q23: Which is the most common of the prokaryotes? Bacteria or
archaea?
A: Bacteria
Q24: What are all cell walls of bacteria composed of?
A: Peptidoglycan and an inner plasma membrane
Q25: What staining technique can be used to determine the nature
of bacterial cell walls?
A: Gram stain
Q26: What do Gram negative bacteria look like?
A: Thin peptidoglycan layer with an outer membrane
Q27: What do Gram positive bacteria look like?
A: Thick peptidoglycan layer with no outer membrane
Q28: What color will a Gram positive bacteria stain? Why
A: Purple
Has a thick cell wall with no outer membrane
