Microbiology MCB 5252 Exam 1 Practice
Questions And Answers.
Vibrio cholerae causes Cholera. The characteristics of the toxin produced by this microorganism
do not include the following
A. It inhibits protein synthesis
B. It's a protein
C. It increases cAMP level
D. It's an enterotoxin
E. It's an exotoxin - Answers✔A. It inhibits protein synthesis
Streak plate is a bacterial culture technique which can be used to:
A. calculate generation time
B. measure optical density of bacteria
C. There is more than one correct answer
D. obtain pure culture
E. count the number of bacteria - Answers✔D. obtain pure culture
Which of the following is NOT true of exotoxins?
A. exotoxins are part of the bacterial cell wall
B. they are usually made of protein
C. Some are enterotoxins
D. Some are neurotoxins
E. All of the above are TRUE of exotoxins - Answers✔A. exotoxins are part of the bacterial cell
wall
Quorum sensing DOES all of the following EXCEPT:
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A. Involves monitoring population density
B. Encourages sporulation
C. Results in formation of biofilm
D. Requires the production of autoinducers
E. Encourages genetic exchange among bacteria - Answers✔B. Encourages sporulation
Which of the following is NOT a general feature of active transport?
A. All of the above are characteristics of active transport
B. Requires a carrier protein
C. Can move molecules against a concentration gradient
D. Requires a form of energy - Answers✔A. All of the above are characteristics of active
transport
During electron transport, excess amount of protons is transported into the cell
A. True
B. False - Answers✔B. False
Which of the following best describes a carrier?
A. an insect harboring a pathogenic organism
B. an organism that normally does not cause infection, but it has the potential to cause infection
given the right condition
C. an organism infected with a virus
D. a microorganism capable of causing an infection
E. a person who harbors a pathogen without exhibiting symptoms - Answers✔E. a person who
harbors a pathogen without exhibiting symptoms
Which of the following is FALSE
A. Obligate anaerobes cannot neutralize the toxic by-products of oxygen metabolism
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B. Human pathogens belongs to mesophile group
C. At the maximum growth temperature for a microorganism, microbial growth is the most
rapid
D. Facultative anaerobes grow faster during aerobic respiration than during anaerobic
respiration - Answers✔C. At the maximum growth temperature for a microorganism, microbial
growth is the most rapid
Which of the following cause(s) mutation by breaking DNA molecule
a- gamma ray
b-UV light
c- X-ray
A. c only
B. a and c
C. a, b, and c
D. a and b
E. b and c - Answers✔B. a and c
Which of the following is TRUE?
A. Proteins are the most abundant compound in the cell
B. Being a cocci or bacilli depeneds on the cell wall structure
C. Both prokaryotic and eukaryotic cells must have ribosome
D. All of these of statements are TRUE
E. All eukaryotic cells must have DNA - Answers✔D. All of these of statements are TRUE
Endotoxin is released when
A. Gram negative pathogens lyse or divide
B. Cells are starved for iron
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C. Cells are lysogenic for the beta phage
D. All of the choices - Answers✔A. Gram negative pathogens lyse or divide
Optical density
A. is directly related to the population of bacteria
B. is used to measure bacterial toxicity
C. None of these
D. is directly related to the length of bacteria
E. is measured by spread plate technique - Answers✔A. is directly related to the population of
bacteria
Which of the following growth media are both selective and differential and favor Gram negative
growth?
A.-Blood
B-MacConkey
C-Mannitol Salt Agar
D-Eosin Methylene blue (EMB)
A. A, B, and C
B. B, C, and D
C. B and D
D. A and C
E. A, B, and D - Answers✔C. B and D
Which of the following statement is not TRUE
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