Microbiology (Bio 370)
Practice Lecture Examination 9
2/10/2014 Kimberly
Name ______________________
I. Define: (do not use examples as definitions)
1. mordant – a chemical (e.g. Iodine) that precipitates a dye in the bacterium.
2. differential media – a medium that grows different bacteria in unique ways for that bug
e.g. color.
3. phenol red – a indicator dye used in media to show pH changes – acid = yellow; base = red
4. synthetic media – expensive media that is chemical defined (i.e. we know exactly what is in it)
5. fastidious bacteria – ‘picky bacteria’ – a narrow growth range of temperature & energy sources
II. Multiple Choice - Choose the most appropriate answer!
1. Kimberly suggested this bug pigments at room temperature but not at 37C: a) Staph aureus;
b) Staph epidermidis; c) Micrococcus roseus; d) Serratia; e) Clostridia
2. The counterstain in the spore stain is: a) safranin; b) methylene blue; c) malachite green;
d) crystal violet; e) carbolfuchsin
3. Kimberly suggested the most common method of separating bacteria species is the: a) quadrant
streak; b) loop dilution; c) pour plate method; d) continuous streaking; e) boiling
4. Which of these is not one of the six “Is” of bacterial study? a) Imbibition; b) inoculation;
c) incubation; d) isolation; e) identification
5. Kimberly suggested most of the colonies of our bugs will be: a) irregular; b) round; c) lobate;
d) rhizoid; e) wrinkled
III. True or False - Correct the false
___F__ 1. The Greek/Latin stem, luteus, refers to green. (yellow)
___T__ 2. Petri dishes are incubated in the inverted state because of condensation problems.
___F__ 3. Kimberly suggested we should Gram stain our cultures in the 4-5 day period. (24-48 hrs)
___T__ 4. Kimberly mentioned the beef brain infusion broth as an example of an enriched medium.
___F__ 5. Difco Manual is referred to as the “bible of bacteriology.” (Bergey’s Manual)
IV. Fill in the blanks.
1. One more time – as magnification goes up, resolution goes ___down__.
2. Draw a side view of an umbonate colony: ______draw a convex colony with ‘nipple’ in center.
3. Draw a concentric colony as a topical view: ___multiple rings of growth from center___
4. Give two items that would make a media ‘selective’: ___salt amount__ & ____type of sugar_.
5. .The acronym, TSA, stands for: _____tryptic soy agar_____.
V. Essay – Give five ways a person could identify a bacterial species.
Color of pigmentation, smell, colony configuration, amount of growth, temperature of
growth, hemolysis of blood agar, pH changes of media, coagulation of substrate, etc.