Pca #2 21DONE PDF

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Pca #2 21DONE...

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Pre-class assignment #1 BIOL 303L, 2020 Microscopy, exercise 1 and 2

1. (1pt) Fill in the box. OBJECTIVE LENS

Name: Brandon Kim

OCULAR PIECE

FINAL MAGNIFICATION

4x

10x

40x

10x

10x

100x

40x

10x 10x

400x

100x

1,000x

2. (2 pts) Explain the difference between magnification and resolving power. - Magnification is defined as the factor that an image appears to be enlarged by. - Resolving power is a property of the lens and is the minimum distance two points can be separated and still be distinct as two separate points 3. (1 pt) How do the filters “work” in the fluorescent microscopes (or what purpose do they serve for allowing us to see different fluors)? - It is usually filtered by the emission filter and the filters “work” by selecting appropriate wavelengths of light that we need. By selecting the wavelength, we are able to see the different fluors. 4. (1 pt) What is the difference between the excitation wavelength and emission wavelength of a fluor? - Excitation wavelength of a fluor is shorter than the emission wavelength 5. (2 pts)You may need to do some outside research on this question. In the buccal cell protocol, step #5 tells you to wash your fixed cells with PBS/tween. a. What kind of a molecule is tween? i. A glycoprotein, PBS/Tween is a buffer to help maintain a constant pH. b. What would happen if you washed your cells in PBS/tween BEFORE you fixed them? i. You would simply wash off your cells 6. (1 pt) What is the purpose of having a negative control? - It is a factor that does not receive any treatment and therefore should not show any change during the experiment. It is used normally to control unknown variables during the experiment and is used as a comparative result. 7. (1 pt) What two molecules are we staining in the buccal cells? - DNA and Fluoresces 8. (1 pt) What tool do you need to calibrate your ocular micrometer? And do you need to only calibrate using one objective? - Stage Micrometer. Using only one objective lens is fine as the ruler does not change when switching between the objective lens magnifications....