Rutgers MICROBIO & ITS APPL Unit 1 Exam

Question 1 Which of the following statements concerning enzymes is FALSE?

They are usually, but not always, proteins.

They always function best at 37°C.

They can be denatured if the pH of their environment is too high or too low.

They form a temporary intermediate compound with a substrate.

They can be used to catalyze a chemical reaction over and over again.

 Question 2 Which of the following describes flash pasteurization?

heating at 63°C for 30 minutes

heating at 72°C for 15 seconds

heating at 72°C for 15 minutes

heating at 134°C for one second

passing liquid through steam at 140°C

 Question 3 What does “narrow spectrum antimicrobial” mean?

The antimicrobial is effective for a very short time.

The antimicrobial is effective against a few microbes.

The antimicrobial can only be administered to a small segment of the population.

The antimicrobial is activated by a specific wavelength in the visible spectrum.

The antimicrobial is effective on all bacteria but not eukaryotes.

 Question 4 Safranin dye is used as the counterstain in ________ stain(s).

the Gram

the endospore

the acid-fast

the flagellar

both the Gram and the endospore

Question 5 Which of the following is NOT a target of drugs that inhibit protein synthesis?

the shape of the 30S ribosomal subunit

interference with alanine-alanine bridges

the enzymatic site of the 50S ribosomal subunit

movement of the ribosome from one codon to the next

the tRNA docking site

 Question 6 At temperatures higher than the maximum growth temperature for an organism,

proteins are permanently denatured.

membranes become too fluid for proper function.

hydrogen bonds within molecules are broken.

hydrogen bonds are broken and proteins are permanently denatured.

hydrogen bonds are broken, proteins are denatured, and membranes become too fluid.

 Question 7 Methicillin is an example of the beta-lactam class of drugs that

disrupts cytoplasmic membranes.

inhibits cell wall synthesis.

inhibits nucleic acid synthesis.

inhibits metabolic pathways.

inhibits protein synthesis.

 Question 8Organisms that can grow with or without oxygen present are

obligate aerobes.

facultative anaerobes.

aerotolerant anaerobes.

obligate anaerobes.

either facultative anaerobes or aerotolerant anaerobes.

 Question 9 An organism that produces catalase enzyme is protected from the harmful effects of

singlet oxygen (1O2).

hydroxyl radical (HO.).

peroxide anion (O22-).

superoxide radical (O2-).

molecular oxygen (O2).

 Question 10 Endospores survive a variety of harsh conditions in part because of the presence of

 

mycolic acid.

lipopolysaccharide.

hopanoids.

dipicolinic acid.

glycoproteins.

 Question 11 A drug is structurally similar to PABA and inhibits folic acid synthesis. It is most likely a(n)

nucleic acid analog.

penicillin.

tetracycline.

azole.

sulfonamide.

 Question 12 Which of the following statements is TRUE of disinfectants?

They are effective in destroying endospores.

They are used on living tissue.

They are used for sterilization.

They are used on inanimate surfaces.

They are only effective for short periods of time (seconds to minutes).

 Question 13 A cell that uses an organic carbon source and obtains energy from light would be called a

photoheterotroph.

lithoautotroph.

photoautotroph.

chemoheterotroph.

chemoautotroph.

 Question 14 Drug-resistant populations of microbes arise when

exposure to drugs selectively kills sensitive cells, allowing overgrowth of resistant cells.

exposure to drugs causes mutations that produce resistance.

resistant cells become numerous in a population due to their greater vigor.

the patient becomes immune to the drug.

synergy between medications occurs.

 Question 15 A(n) ________ organism require(s) oxygen for growth.

anaerobic

facultative anaerobic

aerotolerant

obligate aerobic

aerotolerant and an anaerobic

 Question 16 Anabolic reactions may be characterized as

exergonic.

breaking large molecules into smaller molecules.

forming large molecules from smaller molecules.

producing ATP.

breaking large molecules into smaller molecules to produce ATP.

 Question 17 Which of the following may be a component of bacterial cell walls?

carrageenan

lipoteichoic acids

mycolic acid

tubulin

both lipoteichoic and mycolic acids

 Question 18 It is inappropriate to prescribe antibacterial agents to treat colds or flu because

the microbes involved can develop resistance rapidly.

these diseases are transmitted by endospores, which are difficult to kill.

these diseases exhibit cross resistance.

these diseases are caused by viruses.

these diseases can act synergistically with each other.

 Question 19 An antimicrobial that inhibits cell wall synthesis will result in which of the following?

Cells become more susceptible to osmotic pressure.

Cells cannot attach to their hosts.

Ribosomes lose their function.

The sterols in the cell wall become nonfunctional.

The replication of cells, including cancer cells, slows down.

 Question 20 If a microbiology lab student left the safranin out of the Gram stain procedure, what would be the result?

All cells would be purple.

Gram-positive cells would be purple and Gram-negative cells would be colorless.

All cells would be pink.

Gram-positive cells would be pink and Gram-negative cells would be purple.

Gram-positive cells would be colorless and Gram-negative cells would be pink.

 Question 21 A cell’s G + C ratio is associated with which of the following classification methods?

phage typing

biochemical tests

physical characteristics

analysis of nucleic acids

serological tests

 Question 22 Bacteria of the genus Mycoplasma lack cell walls. What sort of environment do they require for survival?

low temperature

hypotonic

isotonic

hypertonic

a biofilm

 Question 23 Which of the following antifungals works by binding to ergosterol in membranes?

fluconazole

turbinafine

amphotericin B

nystatin

both amphotericin B and nystatin

 Question 24 Why are endospores used to measure the effectiveness of autoclave sterilization?

Endospores are easy to store in the lab until needed.

Endospores are very simple structures and easy to detect.

Endospores are very hard to kill.

Endospores are composed of all the molecules found in living cells.

Endospores of different bacteria are destroyed at different temperatures and can be used to calibrate autoclave temperatures.

 Question 25 Which of the following drugs specifically targets cell walls that contain mycolic acid?

vancomycin

penicillin

methicillin

isoniazid

bacitracin

 Question 26 A phosphate group is transferred from an organic compound to ADP during

oxidative phosphorylation.

substrate-level phosphorylation.

beta-oxidation.

photophosphorylation.

anabolic reactions.

 Question 27 A microbe that grows only at the bottom of a tube of thioglycollate medium is probably a(n)

obligate aerobe.

facultative anaerobe.

aerotolerant anaerobe.

microaerophile.

obligate anaerobe.

 Question 28 Which of the following statements is true of selective toxicity?

Selective toxicity takes advantage of structural differences between host and pathogen.

To be effective, an antimicrobial agent must be more toxic to the patient than the pathogen.

Selective toxicity takes advantage of metabolic differences between host and pathogen.

Antimicrobial agents must target structural differences between host and pathogen and be more toxic to the patient than the pathogen.

Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogen.

 Question 29 Disruption of the normal microbiota can result in infections caused by which of the following microbes?

Mycobacterium

Candida albicans

Clostridium difficile

both Mycobacterium and Clostridium difficile

Candida albicans, Mycobacterium, and Clostridium difficile

 Question 30 A chemical agent that dissolves lipids can damage

cells.

bacterial endospores.

enveloped viruses.

nonenveloped and enveloped viruses.

cells and enveloped viruses.

 Question 31 Which of the following are magnifying lenses?

objectives

oculars

condensers

prisms

both objectives and the oculars

 Question 32 A chemical used to reduce potential pathogens on the skin is a(n)

antiseptic.

disinfectant.

sanitizer.

sterilizing agent.

degermer.

 Question 33 Which of the following bacterial cell structures plays an important role in the creation of biofilms?

 

glycocalyces

flagella

fimbriae

pili

both fimbriae and glycocalyces

 Question 34 An aquatic microbe that can grow only near the surface of the water is probably which of the following?

a phototroph

a heterotroph

a chemotroph

a lithotroph

an anaerobe

 Question 35 A microbiologist inoculates a flask of broth with 1 ml of 100 bacterial cells/ml. The generation time of the species is 1 hour, and there is no lag phase. How long will it be before the culture contains more than 6,000 cells/ml?

12 hours

6 hours

2 hours

4 hours

10 hours

 Question 36 All of the following are common to both the Gram stain and the acid-fast stain EXCEPT

primary stain.

counterstain.

a decolorizing agent.

a chemical mordant.

a decolorizing agent and a counterstain.

 Question 37 Disinfecting agents naturally produced by microorganisms are

aldehydes.

antimicrobials.

halogens.

quats.

triclosans.

 Question 38 Some bacteria have a water-soluble outer slime layer composed of

carbohydrate.

lipid.

peptidoglycan.

protein.

lipoteichoic acid.

 Question 39 Which of the following is bacteriostatic?

heating in an oven at 171°C for an hour

freezing below 0°C

filtration

autoclaving

flash pasteurization

 Question 40 Aseptic means

sterile.

free of all microbes.

clean.

sanitized.

free of pathogens.

 Question 41Methods of microbial control called ________ arrest the growth of microbes.

microbicial

microbistatic

sanitizing

degerming

antiseptic

 Question 42 Which of the following is NOT a characteristic of a genus name?

it is usually an adjective.

it is written before the specific epithet.

it is always capitalized.

it is either underlined or in italics.

it is one of two names used to identify an organism.

 Question 43 Which of the following is an active enzyme?

apoenzyme

cofactor

coenzyme

holoenzyme

subtrate

 Question 44 Which of the following statements concerning cellular metabolism is FALSE?

Energy obtained from nutrients or light is stored in the bonds of ATP.

Enzymes are used in both catabolic and anabolic reactions.

Macromolecules are converted into cell structures via catabolism.

The goal of metabolism is reproduction of the organism.

ATP is used in the formation of macromolecules.

 Question 45 The tetracyclines interfere with

protein synthesis.

cell wall synthesis.

cell membrane component synthesis.

nucleic acid synthesis.

folic acid synthesis.

 Question 46 Which of the following statements concerning glycolysis is TRUE?

It produces ATP by oxidative phosphorylation.

It occurs in the cell membranes of bacteria.

It requires the input of ATP and produces ATP.

It is an alternative to fermentation.

It involves ribulose 5-phosphate as an intermediate.

 

Question 47 Lipid A is a component of

lipopolysaccharides.

plant cell walls.

cytoplasmic membranes.

mycolic acid.

bacterial glycocalyces.

 Question 48 Amoxicillin is very effective for treating infections with Gram-positive bacteria but rarely causes side effects in humans. This is an example of

selective toxicity.

narrow spectrum of action.

a broad-spectrum antimicrobial.

antibiotic resistance.

altruism.

 Question 49 Heat is used to drive the stain into cells in the ________ staining procedure(s).

endospore stain

acid-fast stain

capsule stain

Gram stain

both acid-fast and endospore stains

 Question 50 Sulfanilamide is an antimicrobial drug that mimics the shape of an important substrate for a particular bacterial enzyme, thereby inhibiting the enzyme. This type of inhibition is known as

allosteric inhibition.

competitive inhibition.

allosteric activation.

noncompetitive inhibition.

feedback inhibition.

 Question 51Which of the following classification methods relies on the morphology of organisms?

phage typing

physical characteristics

biochemical tests

analysis of nucleic acids

serological tests

 Question 52 The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid, a β-lactamase inhibitor, is known as

cross resistance.

antimetabolism.

synergism.

selective toxicity.

chemotherapy.

 Question 53 Human pathogens are classified as

thermoduric.

thermophiles.

mesophiles.

hyperthermophiles.

psychrophiles.

 Question 54 Most broad-spectrum antibiotics act by

inhibiting the synthesis of the cell wall.

inhibiting protein synthesis.

inhibiting nucleic acid synthesis.

inhibiting metabolic pathways.

disrupting the cytoplasmic membrane.

 Question 55 Beta-lactam antibiotics have an effect on which of the following types of cells?

animal cells

bacterial cells

fungal cells

virus-infected cells

both animal and fungal cells

 

Question 56 Pyruvic acid is a product of

the Krebs cycle.

fermentation.

glycolysis.

the pentose phosphate pathway.

both fermentation and the Krebs cycle.

 Question 57 Which of the following is an example of pasteurization?

A public toilet is treated with disinfectants.

A surgeon washes her hands before surgery.

Heat is used to kill potential pathogens in apple juice.

An autoclave is used to prepare nutrient agar.

A nurse prepares an injection site with an alcohol swab.

Question 58 Protein synthesis occurs in the

nucleus.

ribosome.

inclusion.

cytoskeleton.

periplasmic space.

Question 59 ATP is expended in which of the following processes?

facilitated diffusion

diffusion

group translocation

active transport

both active transport and group translocation

 Question 60 Which of the following is the most difficult to inactivate?

enveloped viruses

fungus spores

bacterial endospores

nonenveloped viruses

protozoan cysts