BSC 2011L (Bio 2 Lab) Midterm Questions and Answers with
Verified Solutions | Latest Update
QUESTION
What are the steps of the scientific method?
Answer:
1. Make an observation
2. Form a question
3. Form a hypothesis
4. Perform an experiment
5. Analyze the data and draw conclusions
QUESTION
What are the 2 kinds of light microscopes?
Answer:
Dissecting and compound
QUESTION
What are the 2 light sources on a dissecting microscope?
Answer:
- Transmitting light (stage light)
- Incident light (top light)
QUESTION
What are the microscope lenses close to your eye called?
Answer:
Ocular lenses
QUESTION
What magnification are the ocular lenses?
Answer:
10x
,QUESTION
What are the lenses close to the specimen called?
Answer:
Objective lenses
QUESTION
What are the magnifications of the objective lenses on a compound light microscope?
Answer:
4x, 10x, 40x, 100x
QUESTION
Why does the 100x lens need immersion oil?
Answer:
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
QUESTION
What is the name of the part that rotates the objective lenses?
Answer:
Nosepiece
QUESTION
What are the 2 focus knobs called? What magnifications do you use both of them?
Answer:
Coarse adjustment and fine adjustment - Use coarse adjustment on 4x and 10x
- Use fine adjustment on 40x and 100x
QUESTION
What is the name of the part that you put your specimen on?
Answer:
The stage
QUESTION
What adjusts the amount of light that passes through the specimen?
Answer:
Iris diaphragm and dimmer switch
, QUESTION
How do you clean a microscope?
Answer:
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
QUESTION
How should the dimmer switch and stage be set up when first operating a microscope?
Answer:
- 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
QUESTION
How should you adjust the stage and light intensity after the specimen is in place?
Answer:
- 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
QUESTION
What does parfocality mean?
Answer:
The image stays nearly in focus when changing the magnification
QUESTION
Which microscope is parfocal? Which is not?
Answer:
- Compound is parfocal
- Dissecting is not
QUESTION
How do you use immersion oil and the oil immersion lens?
Answer:
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
Verified Solutions | Latest Update
QUESTION
What are the steps of the scientific method?
Answer:
1. Make an observation
2. Form a question
3. Form a hypothesis
4. Perform an experiment
5. Analyze the data and draw conclusions
QUESTION
What are the 2 kinds of light microscopes?
Answer:
Dissecting and compound
QUESTION
What are the 2 light sources on a dissecting microscope?
Answer:
- Transmitting light (stage light)
- Incident light (top light)
QUESTION
What are the microscope lenses close to your eye called?
Answer:
Ocular lenses
QUESTION
What magnification are the ocular lenses?
Answer:
10x
,QUESTION
What are the lenses close to the specimen called?
Answer:
Objective lenses
QUESTION
What are the magnifications of the objective lenses on a compound light microscope?
Answer:
4x, 10x, 40x, 100x
QUESTION
Why does the 100x lens need immersion oil?
Answer:
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
QUESTION
What is the name of the part that rotates the objective lenses?
Answer:
Nosepiece
QUESTION
What are the 2 focus knobs called? What magnifications do you use both of them?
Answer:
Coarse adjustment and fine adjustment - Use coarse adjustment on 4x and 10x
- Use fine adjustment on 40x and 100x
QUESTION
What is the name of the part that you put your specimen on?
Answer:
The stage
QUESTION
What adjusts the amount of light that passes through the specimen?
Answer:
Iris diaphragm and dimmer switch
, QUESTION
How do you clean a microscope?
Answer:
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
QUESTION
How should the dimmer switch and stage be set up when first operating a microscope?
Answer:
- 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
QUESTION
How should you adjust the stage and light intensity after the specimen is in place?
Answer:
- 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
QUESTION
What does parfocality mean?
Answer:
The image stays nearly in focus when changing the magnification
QUESTION
Which microscope is parfocal? Which is not?
Answer:
- Compound is parfocal
- Dissecting is not
QUESTION
How do you use immersion oil and the oil immersion lens?
Answer:
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
