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Microbiology Exam 1 Questions with Answers All Correctly Solved Solutions
1.Q1: A prokaryotic cell may possess each of the following cellular components except: A nucleus
2.Q1: A student has obtained a sample of pond water for study. Using the high power lens, he
observes several cells with nuclei. He can conclude that the cells are NOT bacteria.: True
3.Q1: All cells possess a cell wall.: False
4.Q1: All of the following are true concerning emerging infectious diseases EXCEPT:: They always
involve sporadic cases in endemic areas.
5.Q1: All of the below are examples of a biofilm EXCEPT:: Archaea as part of the plankton
community in the open ocean
6.Q1: All pathogens known to infect humans have been identified at this point in time.: False
7.Q1: Common commercial benefits of microorganisms include synthesis of:: Riboflavin,
acetone, and insulin
8.Q1: Which of the following platforms will we be using in this course? Choose all that apply.:
Blackboard, Microsoft Teams, Pearson, Perusall, and Labster
9.Q1: Development of emerging infectious diseases can be a result of all of the following EXCEPT::
Use of genetically modified foods
10.Q1: Each of the following organisms would be considered a microbe EXCEPT:: Mushroom
11.Q1: If you were setting up an experiment to disprove spontaneous gen- eration in a liquid
medium, which of the following would be essential to the experiment?:
12.Q1: In the name Staphylococcus aureus, aureus is the:: Species name
13.Q1: In which of the following situations would Koch's postulates be uti- lized?: Determination of
2 / 26 the cause of a new emerging disease by scientists studying disease transmission
14.Q1: Infectious disease is almost totally eradicated in our world.: False
15.Q1: Microbes that live stably in and on the human body are called the:: -
Human microbiome or microbiota
16.Q1: Microorganisms are beneficial to humans in all of the following ways EXCEPT::
Pseudomonas, molds and others break down lettuce and strawberries at fridge temperatures
17.Q1: Normal microbiota:: Both colonize the body and take up residence in colon and mouth
18.Q1: Which days of the week are Dr. Duarte's office hours held?: Mondays and Tuesdays (9-
and 1-3)
19.Q1: Proof that a microbe could cause disease is provided by:: Robert Koch
20.Q1: Regarding Louis Pasteur's experiments with the S-neck flask, which of the following
statements is TRUE?: ALL OF THE ANSWERS ARE CORRECT:
- Air exchange was involved.
-A food source was provided.
- The possibility of contamination was removed.
- All preexisting microorganisms were killed.
21.Q1: This course uses Respondus Lockdown Browser and Monitor for tests and quizzes.: True
22.Q1: Spontaneous generation refers to living cells arising from other living cells.: False
23.Q1: The arguments supporting spontaneous generation were finally dis- proved by:: Louis
Pasteur
24.Q1: The first step for directly linking a microbe to a specific disease according to Koch's
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37.Lab1: A student INCORRECTLY streaks the plate according to the diagram below, creating
streaks in the order: a, b, c, d. Which of the following is a streaking error shown in the illustration?: Streak d does NOT draw inoculum from streak c.
38.Lab1: A student properly flames her loop but then forgets to let it cool. Instead, she immediately
inserts the hot loop into her broth culture. What is the most important issue associated with this mistake?: The hot loop may create aerosols when it touches the culture.
39.Lab1: Between brightfield and darkfield using a light microscope, which setting is best to view
the moving bacteria and the bacterial shapes without staining for contrast?: Darkfield
40.Lab1: During the Gram stain, what would most likely occur if you applied alcohol for only 1
second?: Gram-negative bacteria would not decolorize
41.Lab1: How can the doctor rapidly determine if there are bacteria present in the cerebrospinal
fluid (CSF)?: To collect CSF and perform a gram stain.
42.Lab1: How do inclusion bodies assist the bacteria in survival?: They hold nutrients necessary
for the bacteria to survive.
43.Lab1: If a student forgets to flame the mouth of a broth culture tube before transferring culture to
it, what might result?: The medium in the tube might become contaminated.
44.Lab1: Imagine that you forgot to flame the loop before streaking the inocu- lum from the first
quadrant into the second quadrant. What is the most likely consequence of this error?: Too much bacterial growth outside the first quadrant.
45.Lab1: What can you conclude about the gram stained specimen? Choose all answers that apply.:
1)non-acid fast.
2) diplococci
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3) ruled out that taxonomically found in the Staphylococcus genus.
4) produce lipopolysaccharide (LPS), also known as endotoxin.
46.Lab1: What is an inoculum?: The bacteria transferred to a new medium
47.Lab1: What is the gram stain method?: Method of staining used to distinguish bacterial
species into two large groups: gram-positive bacteria and gram-negative bacteria.
48.Lab1: What is the main function of the cell wall?: It acts as a skeleton for plants, protects
the internal contents of the cell, and regulates cell growth.
49.Lab1: What is the outcome of a well-executed gram stain?: Gram positive will appear purple,
and gram negative will appear pink
50.Lab1: Where do we find the teichoic acids?: Gram-positive bacteria
51.Lab1: Where should you label your petri plate with information about the culture?: All labeling
should be done on the bottom portion of the agar plate.
52.Lab1: Which of the following describes aseptic technique?: To manipulate bacteria without
introducing contaminants.
53.Lab1: Which of the following images shows how to properly open a Petri plate to streak the
agar?: Image B (barely open enough for loop to fit and streak)
54.Lab1: Which of the following is an example of how the cell wall protects a bacterial cell?:
Protects from osmotic shock
55.Lab1: Which of the following is neither a eukaryotic nor a prokaryotic cell?: Viruses
56.Lab1: Which of the following observations would suggest that a plate was inoculated with a pure
(axenic) culture?: Isolated colonies are all white in color and about the same size.
57.Lab1: Why are bacteria samples stored in the fridge?: Reduce bacterial growth
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72.Q2: In figure 4.3, which diagram of a cell wall is decolorized by brief exposure to
alcohol?: B (on the right)
73. Q2: In figure 4.3, which diagram of a cell wall is resistant to many antibiotics (e.g. penicillin)?: B
(on the right)
74.Q2: Fimbriae and pilli differ in that: Pilli for DNA and motility
75. Q2: Functions of the glycocalyx include all of the following EXCEPT:: binary fission
76.Q2: In bacteria, photosynthetic pigments are found in:: Chromatophores
77.Q2: In bacterial ribosomes, a small 30S subunit and large 50S subunit come together to produce
the functional 70S ribosome. Why isn't it an 80S ribosome?: S stands for Svedberg units, which indicates the relative rate of sedi- mentation due to size, weight, and shape of a particle. The numbers aren't strictly additive.
78.Q2: Many enzymes in both prokaryotic and eukaryotic cells are compart- mentalized within
organelles.: False
79.Q2: Spheroplasts, protoplasts, and mycoplasms are bacterial cells without cell walls.: True
80. Q2: The internal structure of bacterial and eukaryotic flagella are the same.-
: True
81.Q2: Where are the phospholipids most likely found in a eukaryotic cell?: -
Organelles & surrounding plasma membrane
82.Q2: Where are the phospholipids most likely found in a prokaryotic cell?-
: plasma membrane
83.Q2: Which of the following is NOT found or observed to occur in both mitochondria and
prokaryotes?: cell wall
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84.Q2: Which of the following organelles most closely resembles a prokary- otic cell?:
mitochondria
85.Q2: Which of the following statements is INCORRECT regarding prokary- otic cells?: lack
plasma membrane
86.Q2: Which of the following structures is NOT found in some prokaryotic cells?: cilium
87.Q2: Which structure protects bacteria from being phagocytized?: capsule
88. Q2: Which of the following pairs is mismatched?: ribosomes - carbon storage
89.Q2: You have isolated a motile, gram-positive cell with no visible nucleus. You can safely
assume that the cell:: has a cell wall
90.Q2: An acidic dye:: color is in the negative ion; stains background
91.Q2: Assume you stain Bacillus by applying malachite green with heat and then counterstaining
with safranin. Through the microscope, the green structures are:: endospores
92.Q2: Simple staining is often necessary to improve contrast in which micro- scope?: compound
light
93.Q2: The capsules and flagella of bacteria can be observed in gram-stained smears.: True
94.Q2: The resolution of a microscope can be improved by changing the:: -
wavelength
95.Q2: What is the total magnification of a specimen viewed with a 10x ocular lens and a 45x
objective lens?: 450
96.Q2: Which microscope is used to observe a specimen that emits light when illuminated with
ultraviolet light?: fluorescence
97.Q2: Which of the microscope is used to observe viruses and the internal structure of thinly
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106. Q3: Cyanobacteria are a type of:: photoautotroph
107. Q3: Which compound is being reduced in the reaction shown in Figure
5.1?: NAD+
108. Q3: How would a competitive inhibitor interfere with a reaction involving the enzyme
shown in Figure 5.3?: Site B
109. Q3: Which of the following graphs in Figure 5.5 best illustrates the ac- tivity of an enzyme
that is saturated with substrate?: Graph C (increases then plateaus)
110. Q3: The graph at the left in Figure 5.7 shows the reaction rate for an enzyme at its
optimum temperature. Which graph shows enzyme activity at a higher temperature?: Graph B
111. Q3: (BASED ON PIC) In Figure 5.8, the path labeled "2" is the flow of:: -
protons
112. Q3: (BASED ON PIC) In Figure 5.8, the path labeled "1" is:: plasma mem- brane
113. Q3: (BASED ON PIC) In Figure 5.8, where is ATP produced?: E
114. Q3: (BASED ON PIC) Refer to Figure 5.8. In aerobic respiration, where is water formed?:
D
115. Q3: (BASED ON PIC) What is the most acidic place in Figure 5.8?: A
116. Q3: From the list below, which is NOT produced during the Krebs cycle?-
: NADPH
117. Q3: A bacterial culture grown in a glucose-peptide medium causes the pH to increase. The
bacteria are most likely:: Using the peptides
118. Q3: A urease test is used to identify Mycobacterium tuberculosis be- cause::
Produces urease
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119. Q3: Gallionella bacteria can get energy from the reaction Fe2+ --> Fe3+. This reaction is
an example of:: oxidation reaction
120. Q3: Glycolysis is utilized by cells in both respiration and fermentation.: -
True
121. Q3: If a cell is starved for ATP, which of following pathways would most likely be shut
down?: Pentose phosphate pathway
122. Q3: In general, ATP is generated in catabolic pathways and expended in anabolic
pathways.: True
123. Q3: Increasing the temperature of a reaction will do all of the following EXCEPT::
increase activation energy
124. Q3: (Based on graph) The graph shows the normal reaction rate of an enzyme and the
reaction rate when a competitive inhibitor is present. Which description below explains the appearance of the graph?: Noncompetitive in- hibitors act on other parts of the apoenzyme or on the cofactor and decrease the enzyme's ability to combine with the normal substrate.
125. Q3: Once an enzyme has converted substrates into products, the active site reverts back
to its original form.: True
126. Q3: Researchers are developing a ribozyme that cleaves the HIV genome. The
pharmaceutical agent could be described as:: RNA + catalysis
127. Q3: The advantage of the pentose phosphate pathway is that it produces all of the
following EXCEPT:: 3 ATP's
128. Q3: What is the fate of pyruvic acid in an organism that uses aerobic respiration?:
converted to acetyl CoA
129. Q3: Which of the following is the best definition of fermentation?: partial oxidation of
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137. Lab2: A sample of milk is tested for its bacterial content in a plate count assay. A one-
milliliter sample of the milk is diluted in a 1:10 dilution series. One milliliter of the third dilution is plated in a pour plate. After incubation, the plate has 54 colonies, indicating that the original milk sample contained:: 54,000 cells
138. Lab2: A sample of ocean water is tested for its bacterial content in a plate count assay. A
one milliliter sample of the water is diluted in a 1:10 dilution series. 0.1 milliliter of the second dilution tube is plated in a pour plate. After incubation, the plate has 191 colonies, indicating that the original water sample contained:: 191,000 cells
139. Lab2: A sample of well water is tested for its bacterial content in a plate count assay. A
one milliliter sample of the water is diluted in a 1:10 dilution series. One milliliter of the fourth dilution tube is plated in a pour plate. After incubation, the plate has 83 colonies, indicating that the original water sample contained:: 830,000 cells
140. Lab2: An experiment began with 4 cells in log phase and ended with 128 cells. How many
generations did the cells go through?: 5 generations
141. Lab2: Assume you inoculated 100 cells with a generation time of 20 minutes, into 100 mL
of nutrient broth. You then inoculated 100 cells of the same species into 200 mL of nutrient broth. After incubation for 3 hours, you can reasonably expect to have:: The same number of cells in both
142. Lab2: In one hospital, Pseudomonas aeruginosa serotype 10 infected the biliary tract of
10% of 1300 patients who underwent gastrointestinal endoscopic procedures. After each use, endoscopes were washed with an automatic reprocessor that flushed detergent and glutaraldehyde through the endoscopes, followed by a tap water rinse. P. aeruginosa 10 was not isolated from the detergent, glutaraldehyde, or tap water. What was the source of the infections?: A biofilm in the reprocessor
143. Lab2: In performing a ten-fold dilutions series from a sample containing 10,000 bacteria
14 / 26 per milliliter, the fourth tube in the dilution series will have 10 cells per milliliter.: False
144. Lab2: Pure cultures can easily be obtained on streak plates, even if the desired bacteria
are present in very low concentrations.: False
145. Lab2: Thirty-six colonies grew in nutrient agar from 1.0 ml of undiluted sample in a
standard plate count. How many cells were in the original sample?: 36
146. Lab2: Three cells with generation times of 60 minutes are inoculated into a culture
medium. How many cells are there after 5 hours?: 96 cells
147. Lab2: Which of the following chemical agents is used for sterilization?: -
ethylene oxide
148. Lab2: Which of the following does NOT achieve sterilization?: pasteurization
149. Lab2: Which of the following is NOT a direct method to measure microbial growth?:
metabolic activity
150. Lab2: Which of the following is a limitation of the autoclave?: cannot be used with
heat-liable materials
151. Lab2: Which of the following is an advantage of the direct microscopic count?:
requires no incubation time
152. Lab2: Which of the following is an advantage of the standard plate count?-
: determines the number of viable cells
153. Lab2: Which of the following is an example of a metabolic activity that could be used
to measure microbial growth?: glucose consumption
154. Lab2: Which of the following pairs of microbe classification terms and op- timal growth
temperatures is mismatched?: thermophile - growth at 37 degrees Celsius
155. Lab2: Which of the following regarding antimicrobial control agents is FALSE?: Some
16 / 26 penicillin?: Log phase
165. Q4: In Figure 6.1, which line best depicts a facultative anaerobe in the absence of O2?:
B
166. Q4: In Figure 6.1, which line best depicts a psychrotroph incubated at 0 degrees
Celsius?: B
167. In Figure 6.1, which line best depicts an obligate anaerobe in the presence of O2?: C
168. Q4: (Based on graph) Figure 6.2 shows a typical bacterial growth curve with the y-axis
indicating the log of the number of bacteria and the x-axis indicating time in culture. In the figure, which section (or sections) shows a growth phase where the number of cells dying equals the number of cells dividing?: C
169. IQ4: (Based on graph) In Figure 6.2, which sections of the graph illustrate a logarithmic
change in cell numbers?: B
170. Q4: In Figure 6.3, which tube shows the expected growth pattern for a facultative
anaerobe?: B
171. Q4: In Figure 6.3, which tube shows the expected growth pattern for a
microaerophile?: E
172. Q4: Which graph in Figure 7.2 best depicts the effect of placing the culture in an autoclave
for 15 minutes at time x?: B
173. Q4: Filtration methods, followed by growth of the bacteria trapped on the filters in growth
media, are used to used to count bacteria present in very low concentrations, such as in lakes and streams.: True
174. Q4: If cells are grown in media containing amino acids labeled with radioactive
nitrogen (15N), most of the radioactivity will be found in the cells':: DNA and proteins
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175. Q4: Microorganisms placed in high concentrations of salts and sugars undergo lysis.:
False
176. Q4: Most bacteria grow best at pH:: 7
177. Q4: Most bacteria reproduce by:: binary fission
178. Q4: Patients with indwelling catheters (long-term tubes inserted into body orifices for
drainage, such as through the urethra and into the urinary bladder) are susceptible to infections because:: biofilms develop on catheters
179. Q4: Salts and sugars work to preserve foods by creating a:: hypertonic environment
180. Q4: Some antimicrobial chemicals are considered to be disinfectants and antiseptics.:
True
181. Q4: For the three types of media in Table 6.1, which medium (or media) is/are
chemically defined?: A
182. Q4: The data in Table 6.2 indicate that S. aureus is a(n):: facultative halophile
183. Q4: In Table 7.1, which compound was the most effective against Staphy- lococcus?: C
184. Q4: In Table 7.1, which compound was most effective against E. coli?: E (can't be
determined)
185. Q4: The U.S. Food
and Drug Administration convention when performing pour or spread plate counts is to count only plates with colonies.: - 25- 250
186. Q4: The method is used to indirectly measure microbial growth
filamentous bacteria and molds.: dry weight
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197. Lab4: In the development of drug-resistant bacteria, which of the follow- ing selects for
resistant bacteria?: drug treatment
198. Lab4: Pictured below is the inducible soap operon of the Pseudomonas species growing
in the oncology ward. Imagine the operator has been dam- aged such that the active repressor no longer binds to it. How would this damage affect the growth of Pseudomonas?: Growth on soap would not change much, but the damage would decrease the species' growth elsewhere.
199. Lab4: What do we call circular double-stranded DNA that is able to self-replicate and
has the size of 1-5% of bacterial chromosome?: plasmid
200. Lab4: What is the main source of the free external DNA?: transformation
201. Lab4: What kind of cell functionality that we can find encoded on a plasmid?:
survival
202. Lab4: Which of the following relies on a molecule binding to the repressor to prevent the
repressor from binding to the operator?: induction
203. Lab4: Which of these is NOT required in transduction?: Donor & recipient bacteria must
be in the same place
204. Lab4: (Based on graph)You increase the dose of doxycycline to 2 g total per day and treat
for another 7 days. Again, the patient's health improves at first but then regresses. Below is a graph showing the concentration of bacterial cells (blue line, graphed using the logarithmic scale) in aspirated fluid from her lungs and the drug concentration experienced by the bacteria inside the patient (orange line) over time. Assume that the concentration of pathogenic bacteria is directly related to pati: The 1 g total daily dose was ineffective against all resistant cells, and the 2 g total daily dose was effective against some resistant cells.
205. Lab5: For which enzyme are nucleotides the substrate?: DNA polymerase
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206. Lab5: How many sets of primers are needed for DNA profiling?: 13 primers
207. Lab5: How would the sticky ends of your BioBrick part look like if you cut out plasmid
with XbalX B A one (T'CTAGA) and PstlP S T one (CTGCA'G)?: - CTAG, TGCA
208. Lab5: The number of repeats of each individual's tandem repeated re- gions can be
different creating a specific DNA profile. When using one primer pair in different individuals, which phrase describes the PCR product?: differ- ent lengths
209. Lab5: We have transformed bacteria with a plasmid containing a chlo- ramphenicol
resistance cassette. What happens if we grow these bacteria in a medium containing chloramphenicol?: cells with plasmid survive
210. Lab5: What are plasmids made of?: DNA
211. Lab5: What can a DNA ladder help determine?: length of fragment
212. Lab5: What is the function of primers in a PCR reaction?: bind to specific regions
213. Lab5: What would happen if no polymerase was added to the PCR reac- tion?: no new
DNA
214. lab5: When performing PCR why is it important to change the pipette tip between each
reagent?: avoid cross-contamination
215. lab5: Which word describes the charge of DNA?: negative charge
216. lab5: Why is it possible to distinguish individuals by running these PCR products on a
gel?: different lengths
217. Lab5: (based on image) How many pieces will EcoRI produce from the plasmid shown
in Figure 9.1?: 2
218. Lab5: (based on image) In Figure 9.1, after digestion with the appropriate restriction
