Unit Exam 2

Which of the following should not be included in a medium used to select for a nitrogen-fixing chemoautotroph? A. (NH4)2SO4 B. Na2HPO4 C. KH2PO4 D. MgSO4 E. Glucose

A. (NH4)2SO4

Which of the following statements about algae is false? A. All are unicellular B. Some are capable of sexual reproduction. C. They use light as their energy source D. They use CO2 as their carbon source E. They produce oxygen from hydrolysis of water

A. All are unicellular

Which of the following will NOT destroy prions? A. Boiling B. All of these C. Incineration D. Proteases E. NaOH + autoclaving at 134 C

A. Boiling

Antimicrobial peptides work by A. Disrupting the plasma membrane B. Hydrolyzing peptidogylcan C. Complementary base-pairing with DNA D. Inhibiting cell-wall synthesis E. Inhibiting protein synthesis

A. Disrupting the plasma membrane

If a larva of Echinococcus granulosus is found in humans, humans are the A. Intermediate host B. Infected host. C. None of these. D. Definitive host E. Reservoir

A. Intermediate host

Which of the following statements about drug resistance is false? A. It is found only in gram-negative bacteria B. It may be carried on a plasmid C. It may be transferred from one bacterium to another during conjugation D. It may be due to increased uptake of a drug E. It may be due to enzymes that degrade some antibiotics

A. It is found only in gram-negative bacteria

In the presence of penicillin, a cell dies because A. It undergoes osmotic lysis B. It lacks a cell membrane C. Its contents leak out D. It lacks a cell wall E. It plasmolyzes

A. It undergoes osmotic lysis

Which of the following does not achieve sterilization? A. Pasteurization B. Ethylene oxide C. Dry heat D. Formaldehyde E. Autoclave

A. Pasteurization

Which of the following antibiotics is not bactericidal? A. Polyenes B. Bacitracin C. Cephalosporin D. Rifampins E. Penicillin

A. Polyenes

If you were preparing nutrient agar at home and didnt have an autoclave, what could you use to sterilize the nutrient agar? A. Pressure cooker at 121 C for 15 minutes B. Oven at 121 C for 1 hour C. Boiling for 1 hour D. Bleach E. Hydrogen peroxide

A. Pressure cooker at 121 C for 15 minutes

The cells of plasmodial slime molds can grow to several centimeters in diameter because A. They distribute nutrients by cytoplasmic streaming B. The large surface can absorb nutrients C. They form spores D. They have organelles E. None of these

A. They distribute nutrients by cytoplasmic streaming

Which of the following statements about the Oomycote algae is false? A. They have chlorophyll. B. They reproduce sexually C. They produce zoospores in a sporangium. D. They cause plant diseases E. They form hyphae

A. They have chlorophyll.

More than half of our antibiotics are A. produced by bacteria B. produced by fungi C .produced by Fleming D. None of these E. synthesized in laboratories

A. produced by bacteria

Which of these is not an oxidizing agent? A.None of these B.Hydrogen peroxide C.Chlorine D.Ozone E.Iodine

A.None of these

Protozoan and helminthic diseases are difficult to treat because A.Their cells are structurally and functionally similar to human cells B. They don't reproduce C. They don't have ribosomes D. They have more genes than bacteria E. They replicate inside human cells

A.Their cells are structurally and functionally similar to human cells

Which organism produces catalase and superoxide dismutase? A. none of these B. Aerobe C.Obligate anaerobe D. Anaerobe

B. Aerobe

Bacterial death will result from damage to which of the following structures? A. Cell wall B. All of these C. Proteins D. Nucleic acids E. Plasma membrane

B. All of these

Which enzyme catalyzes the reaction: 2H2O2 -> 2H2O + O2? A. Superoxide dismutase B. Catalase C. None of these D. Oxidase E. Peroxidase

B. Catalase

The life cycle of the fish tapeworm is similar to that of the beef tapeworm. Which of the following is the most effective preventive measure? A. Not swimming in fish-infested waters B. Cooking fish before eating C. Wearing gloves while handling fish D. Refrigerating stored fish E. Salting fish before eating

B. Cooking fish before eating

An organism that can grow photoautotrophically in the light and chemoheterotrophically in the dark A. Oomycote B. Euglena C. Cellular slime mold D. Plasmodial slime mold E. Phytophthora

B. Euglena

Helminthic diseases are usually transmitted to humans by A. Respiratory route. B. Gastrointestinal route C. Aerosols D. Genitourinary route E. Vectors

B. Gastrointestinal route

Which of the following groups of algae does NOT produce compounds that are toxic to humans? A. Diatoms B. Green algae C. Red algae D. All of these produce compounds toxic to humans. E. Dinoflagellates

B. Green algae

Niclosamide prevents ATP generation in mitochondria. You would expect this drug to be effective against A. Gram-positive bacteria B. Helminths C. Viruses D. Mycobacterium tuberculosis E. Gram-negative bacteria

B. Helminths

What do tapeworms eat? A. Intestinal bacteria B. Intestinal contents C. Red blood cells D. Plant matter E. Host tissues

B. Intestinal contents

Which of the following is best to sterilize heat-labile solutions? A.Pasteurization B. Membrane filtration C. Dry heat D. Autoclave

B. Membrane filtration

Which stage immediately precedes the adult? A. Cercaria B. Metacercaria C. Proglottid D. Miracidium E. Redia

B. Metacercaria

All algae are A. Photoautotrophs B. None of these C. Plants D. Unicellular E. Toxic

B. None of these

Which of these antimicrobial agents has the fewest side effects? A. Erythomycin B. Penicillin C. Streptomycin D. Tetracycline E. Chloramphenicol

B. Penicillin

Which of the the following antibiotics is recommended for use against gram-negative bacteria? A. Cephalosporin B. Polymyxin C. Polyenes D. Bacitracin E. Penicillin

B. Polymyxin

Glutaraldehyde is considered one of the most effective disinfectants for hospital use. Which of the following would not be true about glutaraldehyde? A. Safe to tranport B. Stains and corrodes C. Acts rapidly D.Not hampered by organic material E. Attacks all microorganisms

B. Stains and corrodes

Which of the following does not belong with the others? A. Bacitracin B. Streptomycin C. Cephalosporin D. Monobactam E. Penicillin

B. Streptomycin

Bone and tendons for transplant are decontaminated by A. plasma sterilization B. Supercritical fluids C. glutaraldehyde D. peroxygens E. ethylene oxide

B. Supercritical fluids

Which enzyme catalyzes the reaction: O2- + O2- + 2H+ -> H2O2 + O2? A. None of these B. Superoxide dismutase C. Catalase D. Oxidase E. Peroxidase

B. Superoxide dismutase

Fungi, more often than bacteria, are responsible for decomposition of plant materials because A. They prefer a neutral environment B. They can tolerate low moisture conditions C. They can tolerate high osmotic pressure D. They are aerobic E. They have a fermentative metabolism

B. They can tolerate low moisture conditions

Seventeen patients in ten hospitals had cutaneous infections caused by Rhizopus. In all 17 patients, Elastoplast bandages were placed over sterile gauze pads to cover wounds. Fourteen of the patients had surgical wounds, two had venous line insertion sites, and one had a bite wound. Lesions present when the bandages were removed ranged from vesiculopustular eruptions to ulcerations and skin necrosis requiring debridement. Fungi are more likely than bacteria to contaminate bandages because A. They prefer a neutral environment (pH 7). B. They can tolerate low-moisture conditions. C. They cannot tolerate high osmotic pressure D. They have a fermentative metabolism E. They are aerobic

B. They can tolerate low-moisture conditions.

Drug resistance occurs A. All of these B. When antibiotics are used indiscriminately C. When antibiotics are taken after the symptoms disappear D. Against antibiotics and not against synthetic chemotherapeutic agents E. Because bacteria are normal microbiota

B. When antibiotics are used indiscriminately

Which of the following is not effective against nonenveloped viruses? A. All are equally effective B. Chlorine C. Alcohol D. Ethylene oxide E. Ozone

C. Alcohol

Which of the following antimicrobial agents is recommended for use against fungal infections? A. Bacitracin B. Penicillin C. Amphotericin B D. Polymyxin E. Cephalosporin

C. Amphotericin B

In what way are semisynthetic penicillins and natural penicillins alike? A. Both are bactericidal B. Both are resistant to penicillinase C. Both are based on -lactam D. Both are resistant to stomach acids E. Both are broad spectrum

C. Both are based on -lactam

Amoebalike vegetative structures that produce sporangia. A. Tapeworm B. Plasmodial slime mold C. Cellular slime mold D. Euglenozoa E. Ascomycete

C. Cellular slime mold

Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper? A. Sunlight B. None of these C. Gamma radiation D. Microwaves E. UV radiation

C. Gamma radiation

Which of the following methods of action would be bacteriostatic? A. None of these B. Competitive inhibition with folic acid synthesis C. Inhibition of RNA synthesis D. Inhibition of cell wall synthesis E. Injury to the plasma membrane

C. Inhibition of RNA synthesis

The microspora and archaezoa are unusual eukaryotes because they A. Lack nuclei. B. Do produce cysts C. Lack mitochondria D. Don't produce cysts E. Are motile

C. Lack mitochondria

All of the following antibiotics interfere with cell wall synthesis except A. Semisynthetic penicillins B. Vancomycin C. Macrolides D. Natural penicillins E. Cephalosporins

C. Macrolides

Which of the following will NOT preserve foods? A. Osmotic pressure B. Desiccation C. Microwave D. High pressure E. Ionizing radiation

C. Microwave

Which of the following pairs is mismatched? A. Tick - Lyme disease B. Mosquito - encephalitis C. Mosquito - Pneumocystis D. Mosquito - malaria E. Tick - Rocky Mountain spotted fever

C. Mosquito - Pneumocystis

Which of the following is not used for the disinfection of water? A. Ozone B. Chlorine C. None of these D. Copper sulfate E. Gamma radiation

C. None of these

Semisynthesis if these microbial agents has the fewest side effects? A. Chloramphenicol B. Erythomycin C. Penicillin D. Tetracycline E. Streptomycin

C. Penicillin

Multinucleated amoebalike cells that produce funguslike spores A. Ascomycete B. Cellular slime mold C. Plasmodial slime mold D. Tapeworm E. Euglenozoa

C. Plasmodial slime mold

Which one of the following is most useful for disinfecting medical instruments? A. Bisphenols B. Phenol C. Quats D. Chlorine E. Benzoic acid

C. Quats

Which of the following systems in a parasitic helminth is not greatly reduced compared to free-living helminths? A. Nervous system B. Locomotion C. Reproductive system D. All are reduced E. Digestive system

C. Reproductive system

Which of the following organisms would most likely be sensitive to natural penicillin? A. Mycoplasma B. Penicillium C. Streptococcus pyogenes D. Penicillinase-producing Neisseria gonorrhoeae E. L forms

C. Streptococcus pyogenes

A multicellular organism; the digestive tract has one opening A. Cellular slime mold B. Euglenozoa C. Tapeworm D. Ascomycete E. Plasmodial slime mold

C. Tapeworm

The term facultative anaerobe refers to an organism that A. Prefers to grow without oxygen B. Requires less oxygen than is present in the air C. Uses oxygen or grows without oxygen D. Is killed by oxygen E. Doesn't use oxygen but tolerates it

C. Uses oxygen or grows without oxygen

During which growth phase will gram-positive bacteria be most susceptible to penicillin? A. Stationary phase B. Lag phase C. log phase D. death phase E. All phase

C. log phase

The source of nutrients in nutrient agar is A. agar B. nutrient C. peptone and beef extract D. all of these E. peptone and NaCl

C. peptone and beef extract

The first antibiotic discovered was A. Salvarsan B. Sulfa drugs C.Penicillin D. Quinine E. Streptomycin

C.Penicillin

Which concentration of ethyl alcohol is the most effective bactericide? A.30% B. 50% C. 100% D. 70% E. 40%

D. 70%

A definitive host harbors which stage of a parasite? A. Miracidium B. Larva C. All of these D. Adult E. Cyst

D. Adult

Which of the following antibiotics causes misreading of mRNA? A. Oxazolidinone - prevents formation of 70S ribosome B. Chloramphenicol - inhibits peptide bonds at 50S subunit C. Streptogamin - prevents release of peptide from 70S ribosome D. Aminoglycoside - changes shape of 30S units E. Tetracyclines - bind with 30S subunit

D. Aminoglycoside - changes shape of 30S units

A nucleated, unicellular organism; when you change the incubation temperature, it forms filaments with conidiospores A. Plasmodial slime mold B. Tapeworm C. Cellular slime mold D. Ascomycete E. Euglenozoa

D. Ascomycete

Lamisil is an allylamine used to treat dermatomycoses. Lamisil's method of action is similar to that of A. Griseofulvin B. Polymyxin B C. Bacitracin D. Azole antibiotics E. Echinocandins

D. Azole antibiotics

Most of the available antimicrobial agents are effective agains A. Protozoa B. Viruses C. Fungi D. Bacteria E. All of these

D. Bacteria

Yeast infections are caused by A. Penicillium. B. Saccharomycescerevisiae C. Histoplasma D. Candida albicans E. Aspergillus

D. Candida albicans

You see acid-fast oocysts in a fecal sample from a patient who has diarrhea. What is the most likely cause? A. Diatoms B. Giardia C. Entamoeba D. Cryptosporidium E. Taenia

D. Cryptosporidium

Which compound would be the most useful to treat candidiasis? A. Guanine B. Uracil C. Thymine D. Flucytosine E. None of these

D. Flucytosine

Which of the following is an example of a metabolic activity that could be used to measure microbial growth? A. MPN B. Direct microscopic count C.Standard plate count D.Glucose consumption E. Turbidity

D. Glucose consumption

Which one of the following does not belong with the others? A. Ethylene oxide B. Beta-propiolactone C. Glutaraldehyde D. Hydrogen peroxide E. Propylene oxide

D. Hydrogen peroxide

Salts and sugars work to preserve foods by creating a A. Lower osmotic pressure B. Depletion of nutrients C. Hypotonic environment D. Hypertonic environment E. Lower pH

D. Hypertonic environment

In a food chain consisting of the following, which acts as a producer? A. Fungi B. Protozoa C. Slime molds D. Lichens

D. Lichens

Which of the following pairs is not correctly matched? A. CuSO4- algicide B. H2O2- open wounds C. None of these D. Merthiolate- open wounds E. Ag- burns

D. Merthiolate- open wounds

Below are several paired items referring to the heartworm Dirofilaria immitis. Which of the pairs is mismatched? A. Dog - definitive host B. Mosquito - vector C. All of these are correctly matched. D. Mosquito - definitive host E. Dog - sexual reproduction

D. Mosquito - definitive host

Which of the following antibiotics is NOT bactericidal? A. Aminoglycosides B. Penicillin C. Cephalosporins D. Polyenes E. Rifampins

D. Polyenes

Assume you inoculated 100 cells into 100 ml of nutrient broth. You then inoculated 100 cells of the same species into 200 ml of nutrient broth. After incubation for 24 hours, you should have A. can't tell B. More cells in the 100 ml C. More cells in the 200 ml D. Same number of cells in both

D. Same number of cells in both

Which of the following substances is the least effective antimicrobial agent? A. Iodine B. Phenolics C. Cationic detergents D. Soap E. Alcohol

D. Soap

Which of the following treatments is the most effective for controlling microbial growth? A. 63°C for 30 min B. 72°C for 15 sec C. None is effective D. They are equivalent treatments. E. 140°C for 4 sec

D. They are equivalent treatments.

Which of the following is NOT a characteristic of parasitic platyhelminths? A. They are dorsoventrally flattened B. They can be divided into flukes and tapeworms C. They are hermaphroditic D. They have a complete digestive system E. They are multicellular animals.

D. They have a complete digestive system

Which of the following does NOT constitute an advantage of using two antibiotics together? A.It lessens the toxicity of individual drugs B. It can prevent drug resistance C. It allows treatment to be provided prior to diagnosis D. Two are always twice as effective as one E. All of these are advantages

D. Two are always twice as effective as one

Three cells with generation times of 30 minutes are inoculated into a culture medium. How many cells are there after 5 hours? A. 16 B. 1024 C. 48 D. 243 E. 3 x 2^10

E. 3 x 2^10

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? A. 18 B. 9 C. 72 D. 4 E. 36

E. 36

An experiment began with 4 cells and ended up with 128 cells. How many generations did the cell go through? A. 4 B. 32 C. 64 D. 6 E. 5

E. 5

Most bacteria grow best at pH A. 5 B. 14 C. 1 D. 9 E. 7

E. 7

Which of the following statements about fungi is false? A. Most fungi are aerobic B. are heterotrophic C. All fungi have eukaryotic cells D. Few fungi are pathogenic to humans E. All fungi are unicellular

E. All fungi are unicellular

Ringworm is caused by a(n) A. Protozoan B. Trematode C. Cestode D. Nematode E. Ascomycete

E. Ascomycete

Which of the following is not a heavy metal? A. Silver nitrate B. Copper sulfate C. Mercurochrome D. Merthiolate E. Chlorine

E. Chlorine

Which of the following is not a disadvantage of the standard plate count? A. Cells may form aggregates B. Chemical and physical requirements are determined by media and incubation C.None of these D.Requires incubation time E. Determine viable cells

E. Determine viable cells

In mid-December, a woman with insulin-dependent diabetes who had been on prednisone fell and received an abrasion on the dorsal side of her right hand. She was placed on penicillin. By the end of January, the ulcer had not healed, and she was referred to a plastic surgeon. On January 30, a swab of the wound was cultured at 35°C on blood agar. On the same day, a smear was made for Gram staining. The Gram stain showed large (10 µm) cells. Brownish, waxy colonies grew on the blood agar. Slide cultures set up on February 1 and incubated at 25°C showed septate hyphae and single conidia. The most likely cause of the infection is a A. Yeast B. Gram-negative bacterium C. Protozoan D. Parasitic alga E. Dimorphic fungus

E. Dimorphic fungus

Which of the following would be selective against the tubercle bacillus? A. Streptogramin - inhibits protein synthesis B. Bacitracin - inhibits peptidoglycan synthesis C. Streptomycin - inhibits protein synthesis D. Vancomycin - inhibits peptidoglycan synthesis E. Ethambutol - inhibits mycolic acid synthesis

E. Ethambutol - inhibits mycolic acid synthesis

Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt? A. None of these B. Anaerobes C. Psychrophiles D. Thermophiles E. Halophiles

E. Halophiles

Which of the following statements is false? A. Azoles inhibit plasma membrane synthesis B. Amantadine inhibits release of viral nucleic acid C. Fluoroquinolone inhibits DNA synthesis D. Acyclovir inhibits DNA synthesis E. Interferon inhibits glycolysis

E. Interferon inhibits glycolysis

Assume you have isolated a multicellular heterotrophic organism that produces coenocytic hyphae, motile zoospores, and cellulose cell walls. It is most likely a(n) A. Ascomycete fungus B. Zygomycete fungus C. Tapeworm D. Green alga E. Oomycote alga.

E. Oomycote alga.

Producers in hydrothermal vents on the ocean floor use CO2 for their carbon source and what for energy? A. Organic molecules B. Carbon dioxide C.Light D.None of these E. Sulfide

E. Sulfide

The antimicrobial drugs with the broadest spectrum of activity are A. Chloramphenicol B. Macrolides C. Lincomycin D. Aminoglycosides E. Tetracyclines

E. Tetracyclines

Use of antibiotics in animal feed leads to antibiotic-resistant bacteria because A. The antibiotics persist in soil and water B. The few surviving bacteria that are affected by the antibiotics develop immunity to the antibiotics, which they pass on to their progeny C. The antibiotics cause new mutations to occur in the surviving bacteria, which results in resistance to antibiotics D. Bacteria from other animals replace those killed by the antibiotics E. The antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal

E. The antibiotics kill susceptible bacteria, but the few that are naturally resistant live and reproduce, and their progeny repopulate the host animal

Which of the following pairs is mismatched? A. Psychrotroph- growth at 0 C B. Mesophile- growth at 25 C C. None of these D. Psychrophile- growth at 15 C E. Thermophile- growth at 37 C

E. Thermophile- growth at 37 C

The antibiotic actinomycin D binds between adjacent G-C pairs, thus interfering with A. Cellular respiration B. Peptide bond formation C. Plasma membrane function D. Translation E. Transcription

E. Transcription

Which of the following is a limitation of the autoclave? A. Ability to inactivate viruses B. Length of time C. Ability to kill endospores D. Use with glassware E. Use with heat-labile materials

E. Use with heat-labile materials

Which of the following does not belong with the others? A.Sorbic acid B.Pasteurization C.Benzoic acid D.Commercial sterilization E.Acid-anionic detergents

E.Acid-anionic detergents

All of the following act by competitive inhibition except A. Isoniazid B. Ethambutol C. Streptomycin D. None of these E. Sulfonamide

NOT A C. Streptomycin

Which of the following is most resistant to chemical biocides? A. Protozoan cysts B. Mycobacteria C. Viruses with lipid envelopes D. Gram-positive bacteria E. Gram-negative bacteria

Not gram negative B. Mycobacteria