Bio 2010 - Microbiology » Spring 2023 » Lecture Exam 2

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Question #1
Which of the following is slippery outer covering found in some bacteria that protects them from phagocytosis by host phagocytic cells?
A.   peptidoglycan
B.   capsule
C.   flagellum
D.   cell wall
Question #2
Usually, bacteria form more endospores in response to:
A.   nutrient surplus
B.   need for reproduction
C.   adverse environmental stress
D.   colony formation
Question #3
Flemingâ s work and discovery of penicillin in the late 1920â s was a monumental contribution treating human bacterial infections. Approximately one-hundred years later, most bacteria it was originally used to treat have â madeâ their own enzymes to change penicillin and subsequently they have become resistant to its affects. Which of the following is the name of the portion of the antibiotic that resistant bacterial strains and their enzymes â attackâ , rendering the antibiotic harmless?
A.   lipopolysaccharide
B.   peptidoglycan
C.   mycolic acid
D.   beta lactam ring
Question #4
In which growth curve phase would you expect to observe the most endospores in a Bacillus cell culture?
A.   log phase
B.   log, lag, and death phases would all have roughly the same number of endospores.
C.   death phase
D.   lag phase
Question #5
The presence of a bacterial capsule can help a bacterium that possesses it, in all of the following ways EXCEPT help it to:
A.   evade phagocytosis
B.   build biofilms
C.   damage host cells
D.   evade PAMPS activation
E.   move to a new location
Question #6
Bacterial cytoplasm can contain all of the following, EXCEPT:
A.   plasmids
B.   chlorophyll
C.   a nucleus
D.   ribosomes
Question #7
The general name of the functional group of proteins that microorganisms use to anchor themselves to the surface of their hosts are called:
A.   attachments
B.   phagocytosins
C.   hormones
D.   adhesins
Question #8
Suppose that you made an anti-viral drug for SARS-COV2 that prevented it from attaching to the host cell receptor that it typically attaches to, called the ACE2 receptor. In terms of the virus' ability to replicate, which of the following BEST describes what your novel (new) anti-viral drug did to prevent infection?
A.   prevented the virus from leaving the host cell
B.   prevented the virus from attaching to the host cell
C.   destroyed the viral nucleic acid
D.   prevented the virus from entering the host cell
E.   none of these are correct
Question #9
Which of the following bacterial cell structures plays an important role in the creation of biofilms?
A.   fimbriae
B.   flagella
C.   more than one of these are correct
D.   none of these are correct
E.   glycocalyces
Question #10
When flagella are distributed all around a bacterial cell, the arrangement is called:
A.   monotrichous
B.   monotrichous
C.   lophotrichous
D.   peritrichous
Question #11
Which of the following is an internal motile organelle that some bacteria like spirochetes use to propel themselves?
A.   axial filament
B.   plasma membrane
C.   fimbria
D.   pilum
Question #12
Which bacterial cell structures MUST useful antibiotics penetrate in order to kill the bacteria that they are targeted to destroy?
A.   flagella
B.   mitochondria
C.   endoplasmic reticulum
D.   outer plasma membrane
E.   nucleus
Question #13
Which of the following are BOTH flagella and pili made of?
A.   lipids
B.   nucleic acids
C.   protein
D.   carbohydrates
Question #14
Choose the among the answer choices below the pair that BEST completes the following statement: Microorganisms might be virulent (i.e., be capable of causing infectious diseases) because of:
A.   the presence of anatomical structures such as pili.
B.   all of these
C.   the production of various enzymatic activities such as hemolysins and leucocidins
D.   the production of exotoxins or endotoxins.
Question #15
Which of the following would be the BEST term describing bacteria living in salt marshes?
A.   halotolerant
B.   thermophiles
C.   acidophiles
D.   barophiles
Question #16
Bacteria do not always swim aimlessly but are attracted by such nutrients such as sugar and amino acids and are repelled by harmful substances and bacterial waste products. Movement toward chemical attractants and away from repellents is called:
A.   chemotaxis
B.   phototaxis
C.   tumbling
D.   gliding motility
Question #17
Choose the answer that completes the following statement. Electrons have a shorter wavelength than light microscopes. As a result, microscopes using electrons as their energy source have___________ resolution.
A.   no relationship on
B.   lower
C.   the same
D.   higher
Question #18
Which of the following is transmission electron microscopy (TEM) the BEST for viewing?
A.   internal structure of live, living cells.
B.   surface structure of fixed cells.
C.   internal structure of fixed cells.
D.   surface membranes of live, living cells.
Question #19
Which of the following has the highest radiation energy?
A.   light with a long wavelength
B.   light with an intermediate wavelength
C.   light with a short wavelength
D.   radio wavelength
Question #20
Suppose you were using a dark-field microscope to view bacterial cells. Which of the following BEST describes their general appearance using this particular microscope?
A.   dark bacteria on a dark background.
B.   bright bacteria on a bright background.
C.   dark bacteria on a bright background.
D.   bright bacteria on a dark background.
E.   fluorescent bacteria on a dark background.
Question #21
Choose the among the answer choices below the pair that BEST completes the following statement: The instrument that produces a dark image of the specimen against a bright background is called a(n) __________ microscope.
A.   phase-contrast
B.   dark-field
C.   scanning electron
D.   bright-field
E.   transmission electron
Question #22
If you were given a specimen of an active, motile microorganism, which of the following types of microscopy would be the MOST EFFECTIVE in visualizing the live microbe?
A.   fluorescence microscopy
B.   dark-field microscopy
C.   scanning electron microscopy
D.   phase-contrast microscopy
E.   bright-field microscopy
Question #23
Which of the following types of microscopy provides a three-dimensional surface image of viruses and bacterial cells?
A.   fluorescence microscopy
B.   transmission electron microscopy
C.   phase-contrast microscopy
D.   scanning electron microscopy
E.   brightfield microscopy
Question #24
Which of the following forms of light microscopy would you use if you wanted the BEST combination of contrast and resolution necessary to look at LIVING cells?
A.   darkfield microscopy
B.   UV microscopy
C.   scanning electron microscopy
D.   brightfield microscopy
E.   differential interference contrast (DIC)
Question #25
The minimum distance that two objects may be separated and still be detected as two distinct particles, rather than a single particle is:
A.     
B.   the minimum cell size of a cell.
C.   the microscope's magnification.
D.   the microscope's resolution.
E.   the microscope's clarity.
Question #26
Pseudomonas aeruginosa is a common pathogen that infects the airways of patients with cystic fibrosis. It does not grow in the absence of oxygen. Which of the following terms BEST describes its relationship with oxygen?
A.   an obligate anaerobe
B.   an aerotolerant anaerobe
C.   a facultative anaerobe
D.   an obligate aerobe
Question #27
Which of the following segments of the growth curve would starvation proteins be at their HIGHEST detectable levels?
A.   lag phase
B.   death phase
C.   stationary phase
D.   exponential phase
Question #28
Which of the following would BEST describe a culture broth tube that was very turbid at the surface but clear throughout the rest of the tube?
A.   the organisms in the culture broth tube are aerobes
B.   the organisms in the culture broth tube should be grown in an anaerobic chamber
C.   the organism in the culture broth tube cannot produce superoxide dismutase and/or catalase enzymes
D.   the organisms in the culture broth tube cannot tolerate oxygen
Question #29
You isolate bacteria from a mine draining water and measure the pH from this water at pH = 2.0. Which of the following growth terms BEST describes this organism?
A.   obligate anaerobes
B.   acidophiles
C.   neutrophiles
D.   alkaliphiles
Question #30
An aquatic microbe that can grow only at the surface of the water is probably which of the following?
A.   a chemoheterotroph
B.   a heterotroph
C.   a chemotroph
D.   a phototroph
Question #31
Quorum sensing is used by bacterial cells to determine which of the following?
A.   the speed of water flow
B.   the availability of nutrients
C.   the size of the population
D.   the density of the population
Question #32
Which of the following is the BEST reason why psychrophilic bacteria will not grow in hyperthermophilic environments?
A.   they lack the correct enzymes
B.   they lack the correct pH
C.   they lack the correct atmospheric pressure
D.   they lack the correct nucleus
Question #33
Choose the among the answer choices below the pair that BEST completes the following statement: A cell placed in a(n) __________ solution will __________ water.
A.   isotonic; gain
B.   hypertonic; gain
C.   isotonic; lose
D.   hypotonic; gain
E.   hypotonic; lose
Question #34
In lecture, we described the similarity in appearance of bacterial growth curves and the stages of human infection curve. Which of the following BEST explains why these two curves are similar in shape and size?
A.   exponential bacteria growth causes the illness human infection stage
B.   lag stage bacteria growth causes the illness human infection stage
C.   lag stage bacteria growth causes the convalescence human infection stage
D.   exponential bacteria growth causes the decline human infection stage
Question #35
Which of the following BEST describes what happens to cells numbers and density in the exponential growth phase?
A.   they show an overall decreasing trend
B.   they are both constant
C.   they first increase then decreases
D.   they both double at a constant rate
Question #36
You have isolated a bacterium from the bottom from a deep ocean trench, in a tropical location. Which of the following terms BEST describes its physical or chemical growth requirements?
A.   more than one of these are correct
B.   halophile
C.   psychrophil
D.   barophil
E.   alkalinophil
Question #37
Why is the exponential phase of growth curve of bacteria limited in its duration?
A.   due to the exhaustion of nutrients
B.   more than one of these are correct
C.   due to the rise in cell density
D.   due to the accumulation of toxic metabolites
Question #38
During which growth curve phase would penicillin, an antibiotic that inhibits cell-wall synthesis, be most effective?
A.   death phase
B.   stationary phase
C.   exponential or log phase
D.   lag phase
Question #39
Which of the following is a characteristic shared by BOTH endospores and vegetative cells?
A.   radiation resistance
B.   resistance to drying
C.   heat resistance
D.   presence of DNA
E.   low metabolic activity
Question #40
Some species of bacteria can grow in hot water, such as hot tubs that people have in their homes, some of which reach temperatures in excess of 100°F. Which of the following BEST describes bacteria isolated from such a hot tub?
A.   mesophiles
B.   psychrotrophs
C.   hyperthermophiles
D.   thermophiles
Question #41
In which environment are you most likely to encounter acidophiles?
A.   a hot vent at pH 1.5
B.   milk at pH 6.5
C.   human blood at pH 7.2
D.   human intestine at pH 8.5
Question #42
Which of the following BEST defines the growth phase period between inoculation of bacteria and beginning of multiplication in a culture medium?
A.   log phase
B.   stationary phase
C.   decline phase
D.   lag phase
Question #43
A microbiology student noticed that a culture broth tube was very turbid at the surface but clear throughout the rest of the tube. Which of her following conclusions about the growth of these organisms is CORRECT?
A.   the broth is sterile.
B.   they are aerobes.
C.   they cannot tolerate oxygen.
D.   they should be grown in an anaerobic chamber.
E.   they cannot produce superoxide dismutase and/or catalase.

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