BIOL 2420 Microbiology Fall 2011 Dr. Farnsworth
LAB QUIZ 1. EXERCISES 1-4 Total: 25 points
Name:……………………………………………………………………………………..
This is a take-home lab quiz. You can do it alone or discuss with your classmates. However, all writing
has to be your own (i.e. You cannot copy what someone else has written down and claim it for
yourself).
Duplicate quizzes will be awarded a zero for ALL duplicates. No excuses.
1. Given that the eyepiece lens has a magnification of 10X, what would be the magnification of
each of the following objective lenses? (4 points)
a. 4X
b. 10X
c. 40X
d. 100X
2. T/F It is alright to use kimwipes to clean the objective lenses of a microscope (2 points)
3. Which objective is the oil immersion lens? (1 point)
4. Which parts of the microscope would you use for the following functions: (4 points)
a. Transport the microscope from the cupboard to your bench.
b. Hold the slide in place and move it from side to side.
c. Adjust the amount of light reaching the object.
d. Move the stage to focus on the object under the 100X.
5. You have two dyes labeled X and Y and would like to know which one is positive and which is a
negatively charged. Briefly describe the methods you would use to do this given a bacterial
smear. (6 points)
6. You have learned to isolate bacteria using the streak plate technique and are excited to view
your results from streaking a pure culture. However, when you pick up your plate the next day,
you notice something is wrong. Explain what could have happened in each of the following
situations (8 points)
a. The bacteria colonies have all joined together and there’s a pool of water on your plate.
b. There are many bacterial colonies in every single quadrant of the plate.
c. Only the first quadrant has a lawn of bacteria while the rest do not.
d. There’s a hairy looking growth on your plate.