Compre Flashcards
(315 cards)
Which of the following is based on phenotypic identification?
a. Base sequencing
b. DNA fingerprinting
c. Nucleic acid testing
d. Antimicrobial susceptibility testing
D
Which of the following terms refers to the negatively-charged content of a Gram-positive cell wall that contributes to the latter’s charge?
a. Peptidoglycan
b. Teichoic acid
c. Lipoteichoic acid
d. Muramic acid
B
Which of the following culture media would be best used to isolate bacteria capable of distinguishing carbohydrates fermentation?
a. Blood agar
b. Chocolate agar
c. MacConkey agar
d. CNA blood agar
C
Which of the following serologic tests is considered as sensitive and specific method for detection of antibodies against certain pathogens?
a. Particle agglutination test
b. Flocculation test
c. ELISA
d. Fluorescent Antibody test
e. Western Blot
C
What do you call the process of prokaryotes in which one cell (the parent cell) splits in half to become two daughter cells?
a. Binary fusion
b. Binary fission
c. Meiosis
d. Mitosis
B
Which cell structure is an essential part of genetic transfer (conjugation)?
a. Fimbriae
b. Sex pilus
c. Flagella
d. Cilia
B
What intracellular structure that allows organisms to withstand extreme conditions? a. Capsule
b. Plasmid
c. Endospores
d. Murein
C
The cellular membrane contains
a. Matrix porins
b. Endotoxins
c. Glycocalyx
d. Enzymes involved in bacterial oxidative phosphorylation
e. All of the above
D
What kind of stains are commonly used in the study of bacteria?
a. Acidic dyes
b. Basic dyes
c. Indirect stains
d. Negatively charged stains
B
Of the following, which one is NOT found in prokaryotic cells?
a. Cell membrane
b. Chromosomes
c. Mitochondria
d. Plasmids
C
Each of the following statements is true about the mechanism of action of antibiotics on bacteria, EXCEPT
a. Chloramphenicol affects the large subunit of bacterial ribosomes, which is different from the large subunits of eukaryotes
b. Streptomycin affects the DNA polymerases of bacteria but not that of human cells
c. Penicillin affects bacteria rather than human cells because bacteria have cell wall, while human cells do not
d. Linezolid affects bacterial initial ribosome synthesis but not that of eukaryotic cells
B
All of the following are correct concerning culture media, EXCEPT
I. Blood agar and chocolate agar are examples of complex, selective media, that supports the growth
of many different bacteria
II. MacConkey agar is a differential media, which differentiate lactose and non-lactose fermenters of
Enterobacteriaceae
III. If the clinical samples are from non-sterile site (e.g. sputum) it is recommended to use selective
media like Columbia Colistin Nalidixic agar
IV.Most pathogens like bacteria, parasites and viruses can be isolated on a solid-agar containing media
a. I and II
b. III and IV
c. I and IV
d. II and III
C
Each of the following statements are true regarding murein later, EXCEPT
a. It has a backbone composed of alternating units of muramic acid and acetylglucosamine
b. It can be degraded by lysozyme
c. Cross-links between the tetrapeptides involve d-alanine
d. It is thinner in gram positive than in gram negative cells
D
Which of the following statements precisely describes the comparison of bacterial, fungal and human cells?
a. Human and fungal cell walls have similar cell, in contrast to bacteria whose cell wall contains peptidoglycan
b. Human and fungal cells have similar ribosomes, whereas bacterial ribosomes are different
c. Human cells undergo meiosis, whereas neither bacteria nor fungi do.
d. Human cells and bacterial cells have mitochondria, whereas fungal cells do not
B
Which of the following statements is incorrect regarding bacterial endospores?
a. Endospores are formed under adverse environmental conditions such as absence of carbon
source.
b. Endospores are resistant to boiling and sometimes UV radiation
c. Endospores are formed primarily by rod-shaped organisms like E. coli and C. diphtheriae
d. Endospores are metabolically inactive and contain dipicolinic acid and calcium.
C
Assume you stain Clostridium perfringens from an abscess by applying malachite green with heat and counterstain with safranin O. In the microscope, the green structures that taken up the malachite green are called?
a. Cell walls
b. Flagella
c. Endospores
d. Capsules
e. Impossible to identify
C
Bacterial surface structures that show antigenic diversity include each of the following, EXCEPT
a. Murein layer
b. Capsules c. Flagella d. Pili
A
All of the following are effects of Lipid A, EXCEPT a. Fever
b. Activation of coagulation cascade c. Hypotension
d. Opsonization and phagocytosis
D
Which of the following pairs is mismatched regarding the chemical subunits of glycocalyx for each bacterium?
a. Bacillus anthracis: D glutamic acid
b. Haemophilus influenzae: muramic acid
c. Neisseria meningitidis: sialic acid
B
Which type of plasmids turns the host of the plasmid into a pathogen?
a. Virulence plasmid
b. Resistance plasmid
c. Fertility plasmid
d. Col plasmid
A
Which of the following nucleic acid based technique is considered as simplest and commonly used in epidemiologic studies?
a. Plasmid analysis
b. Southern blot analysis
c. Ribotyping
d. Western blot analysis
A
Which of the following pairs is mismatched?
a. Immunofluorescent Assay: Direct Fluorescence assay for T. pallidum
b. Particle agglutination test. Widal test for S. Typhi
c. Western blot: band lines on gp41 and p24 for HIV
d. Flocculation test RPR and VDRL for T. pallidum
B
The bacterial fimbriae that are present on the outer cell surface, and there are used for
a. Cell motility
b. Sexual reproduction
c. Adherence and exchange of genetic information
d. Adherence to surfaces
D
. In gram negative bacteria, the transport of nutrients is usually facilitated by specific binding proteins located in periplasmic space, while gram positive cells the binding proteins are attached to the outer surface of the cell membrane which of the following transport mechanism is responsible for this action?
a. Passive transport
b. Special transport process
c. Active transport
d. Group translocation
C