Microbiology -  Practical Practice Questions

Topics:  see Study Objectives listed at beginning of LAB MANUAL for more specific information about WHAT EXERCISES will be covered for each practical.

Try to answer these questions without help from notes or books.  Answers at end.

1.  What do you call these filaments found in fungi?

stain2.  This is an acidfast stain.  Is it acid fast or NONacid fast?

3.  Identify this stain.

4.  What is the stain procedure that malachite green is used for?  What is its function?

yeast5. Name this fungus used in lab.

6.  How are protozoa categorized into the 4 major groups?

7.  What's the arrangement?

malaria8.  The genus name of this protozoan ______, in the class _________  Motile or nonmotile?

9.  This worm is a----hookworm, tapeworm, fluke, filarial worm, pinworm?

10.  TTC agar.  Which organism is the organism motile--left, right, or both? motility

11.  Give the gram reaction and shape of the bacterium.gram stain

gram stain12.  Give the gram stain, shape, and arrangement of this organism.

13.   Name the labeled structure on the microscope, and its function. What is the total magnification if you were viewing a specimen using this objective lens? microscope

14.  What type of flagellation?
flagella stain

15.  Name the dye used to color the spores. spore stain

16.  Work this dilution problem, solving for the number of bacteria per ml. of specimen.

17.  What is this technique---streak plate, spread plate, or pour plate?  How do you know?

agar plate


  18.  Name a simple stain.

19. Good streak plate or bad streak technique?  Explain.  plate

 spec  20.This machine is called a ________.  It measures __________, which directly relates to cell density.

21.  Identity the citrate reaction---+ or -.

22.  Is this a - or a + indole test?  What is the reagent used?

23.Why is tam ethylene blue indicator strip placed into the gasPak/anaerobic jar?  

24.  In the amino acid decarboxylase tests, is the amino end OR the carboxyl end of the a.a. chopped off?

25.  Is the organism + or - for ornithine decarboxylase?

26.  Is this organism + for acid production in the methyl red test?biochem

27.  Determine the number of viruses per ml. of specimen.

28.  Which reaction is + for catalasecatalase

milk29.  Is this organism + or - for caseinase?

30.  Which organism--left or right--is + for coagulase?  Name a bacterial genus for which this test is important.

31. Which organism is + on this methylene blue lipid agar plate?  lipid hydrolysis

32.  What's the difference between these 2 nitrate tubes (no zinc added)?

33.   What are these holes called? What is the name of the organism doing it?

34.  What does the acronym IMViC stand for??

35.  Does this SIM medium show + or - for hydrogen sulfide gas?

36.  Which tube is + for esculin use? bile

litmus milk37. What's the difference in these 2 reactions of litmus milk (held at a slanted position to see better)?

38.  Is this organism + or - for the VP test?  The reagents are named what?

39.    What does this nitrate test mean?

40.  Name this hemolytic reaction---alpha, beta, or gamma?  beta


1. hyphae
2.  acidfast
3.  capsule
4.  primary dye for spore stain
5. Saccharomyces
7.  chains
8.  Plasmodium, apicomplexa, nonmotile
10. both
11.  gram - spiral
12.  G+ cocci, clusters
  revolving nosepiece, 1000X magn.
14.  peritrichous
15.  malachite green
16.  set up of problem:       70 colonies   = 7,000,000,000 or  7 X 10
                                       1/10  X  0.1ml
17. pour plate, colonies within agar
18.  crystal violet, meth. blue, safrinin, malachite green, carbol fuschin
19.  bad technique---no isolation of colonies
 20. spectrophotometer.  Measures absorbance of light, directly related to cell density. 

21.  +
22.  -, Kovacs
  indicates presence or absence of oxygen in the Gaspak anaerobic jar
24.  carboxyl
25.  -
26.  yes, + for acid from glucose use
27.  280,000,000/ml
29. +
30. right tube, Staph genus
31.  left
32.  left--N2 gas, right--nitrate reduced to nitrite
33. plaques, bacteriophages
34.  indole, methyl red, voges-proskauer, citrate
35.  -
36.  right tube is + for esculin, shown by the dark brown slant
37.  bottom shows acid from lactose use, top shows an acid curd (acid + casein coagulation)
38.  + , Barritt's A and B reagents
39. no nitrate reduced
40.  beta--complete hemolobin breakdown