Microbiology Flashcards

The property of endospores that led to confusion in the experiments on spontaneous generation is their

1. small size.

2. ability to pass through cork stoppers.

3. heat resistance.

4. presence in all infusions.

5. presence on cotton plugs.

Heat resistance

The Golden Age of Microbiology was the time when

1. microorganisms were first used to make bread.

2. microorganisms were first used to make cheese.

3. most pathogenic bacteria were identified.

4. a vaccine against influenza was developed.

5. antibiotics became available.

Most pathogenic bacteria were identified

If all prokaryotes were eliminated from the planet,

1. animals would thrive because there would be no disease.

2. archaea would thrive because there would be no competition for nutrients.

3. all animals would die.

4. animals and archaea would thrive.

All animals would die

he following are emerging infectious diseases except

1. smallpox.

2. hepatitis C.

3. Lyme disease.

4. COVID-19.

5. mad cow disease.

Smallpox

All of the following are biological domains except

1. Bacteria.

2. Archaea.

3. Prokaryota.

4. Eukarya.

Prokayota

Which name is written correctly?

1. staphylococcus aureus

2. escherichia Coli

3. Staphylococcus epidermidis

4. bacillus Anthracis

5. Clostridium Botulinum

Staphylococcus epidermidis

Members of which pairing are most similar in appearance to each other?

1. fungi and algae

2. algae and archaea

3. archaea and bacteria

4. bacteria and viruses

5. viruses and algae

Archaea and bacteria

If you wanted to increase your chances of obtaining a member of the Archaea (rather than a member of another domain), which would be the best site to obtain a sample?

1. intestine of an elephant

2. skin of an elephant

3. a 95°C hot spring in Yellowstone

4. a 45°C hot spring in Hawaii

5. a raw hamburger patty

A 95-degree C hot spring in Yellowstone

Viruses

1. contain both protein and nucleic acid.

2. infect only eukaryotic cells.

3. can grow in the absence of living cells.

4. are generally the same size as prokaryotes.

5. always kill the cells they infect. 

Contain both protein and nucleic acid.

Antonie van Leeuwenhoek could not have observed

1. roundworms.

2. Escherichia coli.

3. yeasts.

4. Viruses.

Viruses

Which bacterial cell component provides the best barrier for preventing most molecules from passing through it?

1. Peptidoglycan

2. Capsule

3. Cytoplasmic membrane

4. Slime layer

Cytoplasmic membrane

Endotoxin is associated with

1. Gram-positive bacteria.

2. Gram-negative bacteria.

3. the cytoplasmic membrane.

4. endospores.

Gram-negative bacteria

The “O157” in the name E. coli O157:H7 refers to the type of O antigen. From this information you know that E. coli

1. has a capsule.

2. is a rod.

3. is a coccus.

4. is Gram-positive.

5. is Gram-negative.

Is Gram-negative

Eliminating which structure is always deadly to cells?

1. Flagella

2. Capsule

3. Cell wall

4. Cytoplasmic membrane

5. Fimbriae

Cytoplasmic membrane

If you interfered with the ability of a Bacillus species to form endospores, what would be the result? The bacterium would no longer be

1. able to multiply.

2. antibiotic resistant.

3. Gram-positive.

4. Gram-negative.

5. able to withstand boiling water.

Able to withstand boiling water

If a virus mimics a ligand that normally participates in receptor-mediated endocytosis, the virus might

1. prevent pinocytosis.

2. be taken up by the cell.

3. damage the cytoplasmic membrane.

4. cause the cell to form pseudopods.

5. damage the receptor.

Be taken up by the cell

The antibiotic erythromycin prevents protein synthesis in bacterial cells. Based on this information, which of the following might be targeted by the drug?

1. 80S ribosomes

2. 70S ribosomes

3. 60S ribosomal subunit

4. 50S ribosomal subunit

5. 40S ribosomal subunit

1. 1, 3

2. 1, 4

3. 2, 3

4. 2, 4

5. 2, 5

2,4

If a eukaryotic cell were treated with a chemical that destroys tubulin, all of the following would be directly affected except

1. actin.

2. cilia.

3. eukaryotic flagella.

4. microtubules.

5. More than one of these

Actin

Which of the following is most likely to be used in a typical microbiology laboratory?

1. Bright-field microscope

2. Confocal scanning microscope

3. Phase-contrast microscope

4. Scanning electron microscope

5. Transmission electron microscope

Bright-field microscope

When a medical technologist wants to determine if a clinical specimen contains a Mycobacterium species, which should be used?

1. Acid-fast stain

2. Capsule stain

3. Endospore stain

4. Gram stain

5. Simple stain

Acid-fast stain

If there are 103 cells per mL at the middle of log phase, and the generation time of the cells is 30 minutes, how many cells will there be 2 hours later?

     o) 2 × 103

1. 4 × 103

2. 8 × 103

3. 1.6 × 104

4. 1 × 107

1.6 × 104

Compared with their growth in the laboratory, bacteria in nature generally grow

o) more slowly

a) faster.

b) at the same rate

More slowly

Cells are most sensitive to penicillin during which phase of the growth curve?

     o) Lag

1. Exponential

2. Stationary

3. Death

4. More than one of these

Exponential

Which best describes the intestinal tract?

o) An open system with a chemically defined medium

a) An open system with a complex medium

b) A closed system with a chemically defined medium

c) A closed system with a complex medium

An open system with a complex medium

E. coli, a facultative anaerobe, is grown for 24 hours on the same type of solid medium, but under two different conditions: one aerobic, the other anaerobic. The size of the colonies will be

      o) the same under both conditions.

1. larger when grown under aerobic conditions.

2. larger when grown under anaerobic conditions.

Larger when grown under aerobic conditions

The generation time of a bacterium was measured at two different temperatures. 

Which results would be expected of a thermophile?

      o) 20 minutes at 10°C; 220 minutes at 37°C

1. 220 minutes at 10°C; 20 minutes at 37°C

2. no growth at 10°C; 20 minutes at 37°C

3. 20 minutes at 45°C; 220 minutes at 65°C

4. 220 minutes at 37°C; 20 minutes at 65°C

220 minutes at 37 degrees C; 20 minutes at 65 degrees C

Which of the following is false?

     o) E. coli grows faster in nutrient broth than in glucose-salts medium.

1. Organisms require nitrogen to make amino acids.

2. Some eukaryotes can fix N2.

3. An organism that grows on ham is halotolerant.

4. Blood agar is used to detect hemolysis.

Some eukaryotes can fix N2

If the pH indicator were left out of MacConkey agar, the medium would be

      o) complex.

1. differential.

2. defined.

3. defined and differential.

4. complex and differential. 

Differential

A soil sample is placed in liquid and the number of bacteria in the sample determined in two ways: (1) colony count and (2) direct microscopic count. How would the results compare?

     o) Methods 1 and 2 would give approximately the same results.

1. Many more bacteria would be estimated by method 1.

2. Many more bacteria would be estimated by method 2.

3. Depending on the soil sample, sometimes method 1 would be higher and sometimes method 2 would be higher.

Depending on the soil sample, sometimes method 1 would be higher and sometimes method 2 would be higher.

If the concentration of E. coli in a broth is between 104 and 106 cells per mL, the best way determine the precise number of living cells in the sample would be to

     o) use a counting chamber.

1. plate out an appropriate dilution of the sample on nutrient agar.

2. determine cell number by using a spectrophotometer.

3. Any of these three methods would be satisfactory.

4. None of these three methods would be satisfactory.

Determine cell number by using a spectrophotometer

Unlike a disinfectant, an antiseptic 

     o) sanitizes objects rather than sterilizes them.

1. destroys all microorganisms.

2. is non-toxic enough to be used on human skin.

3. requires heat to be effective.

4. can be used in food products.

Is non-toxic enough to be used on human skin

The D value is defined as the time it takes to kill 

      o) all microbial cells in a population.

1. all pathogens in a population.

2. 99.9% of a microbial population.

3. 90% of a microbial population.

4. 10% of a microbial population.

90% of a microbial population

Which of the following is the most resistant to destruction by chemicals and heat? 

     o) Bacterial endospores

1. Fungal spores

2. Mycobacterium tuberculosis

3. E. coli

4. HIV

Bacterial endospores

Ultraviolet light kills bacteria by 

      o) generating heat.

1. damaging DNA.

2. inhibiting protein synthesis.

3. damaging cell walls.

4. damaging cytoplasmic membranes.

Damaging DNA

Which concentration of alcohol is the most effective germicide? 

      o) 100%

1. 75%

2. 50%

3.   25%

4. 5%

75%

All of the following could be used to sterilize an item except

       o) boiling.

1. incineration.

2. Irradiation.

3. Sporocides.

4. Filtration.

Boiling

All of the following are routinely used to preserve foods except 

      o) high concentrations of sugar.

1. high concentrations of salt.

2. benzoic acid.

3. Freezing.

4. ethylene oxide.

Ethylene oxide

Aseptically boxed juices and cream containers are processed using which of the following heating methods? 

      o) Commercial canning

1. High-temperature–short-time (HTST) method

2. Autoclaving

3. Ultra-high-temperature (UHT) method

4. Boiling

Ultra-high-temperature (UHT) method

Commercial canning processes are designed to ensure destruction of which of the following? 

     o) All vegetative bacteria

1. All viruses

2. Endospores of Clostridium botulinum

3. E. coli

4. Mycobacterium tuberculosis

Endospores of Clostridium botulinum

Which of the following is false? 

     o) A high-level disinfectant cannot be used as a sterilant.

1. Critical items must be sterilized before use.

2. Low numbers of endospores may remain on semicritical items.

3. Standard sterilization procedures do not destroy prions.

4. Quaternary ammonium compounds can be used to disinfect food preparation surfaces.

A high-level disinfectant cannot be used as a sterilant

Which of these factors do/does not affect enzyme activity?

1. Temperature

2. Inhibitors

3. Coenzymes

4. Humidity

5. pH

Humidity

Which of the following statements is false? Enzymes

1. bind to substrates.

2. lower the energy of activation.

3. convert coenzymes to products.

4. speed up biochemical reactions.

5. can be named after the kinds of reaction they catalyze.

Convert coenzymes to products

Based on the name, NADH dehydrogenase is

1. a vitamin that oxidizes NADH.

2. a vitamin that reduces NADH.

3. a vitamin that produces NADH.

4. an enzyme that oxidizes NADH.

5. an enzyme that reduces NADH.

An enzyme that oxidizes NADH

What is the end product of glycolysis?

1. Glucose

2. Citrate

3. Oxaloacetate

4. α-Ketoglutarate

5. Pyruvate

Pyruvate

The central metabolic pathway(s) is/are

1. glycolysis and the TCA cycle only.

2. glycolysis, the TCA cycle, and the pentose phosphate pathway.

3. glycolysis only.

4. glycolysis and the pentose phosphate pathway only.

5. the TCA cycle only.

Glycolysis, the TCA cycle, and the pentose phosphate pathway

Which of these pathways gives a cell the potential to produce the most ATP?

1. TCA cycle

2. Pentose phosphate pathway

3. Lactic acid fermentation

4. Glycolysis

TCA cycle

In fermentation, the terminal electron acceptor is

1. oxygen (O2).

2. hydrogen (H2).

3. carbon dioxide (CO2).

4. an organic compound.

An organic compound

In the process of oxidative phosphorylation, the energy of a proton motive force is used to generate

1. NADH.

2. ADP.

3. ethanol.

4. ATP.

5. Glucose.

ATP

If a bacterium loses the ability to produce FADH2, which of the following cannot continue?

1. Biosynthesis

2. Glycolysis

3. The pentose phosphate pathway

4. The TCA cycle

5. Fermentation

The TCA cycle

Degradation of fats as an energy source involves all of the following except

1. β-oxidation.

2. acetyl-CoA.

3. glycerol.

4. lipase.

5. transamination.

Transamination

Which of the following is the newest taxonomic unit?

      o) Strain

1. Family

2. Order

3. Species

4. Domain

Domain

If an acid-fast bacterium is detected in a clinical sample, then the organism could be

      o) Cryptococcus neoformans.

1. Mycobacterium tuberculosis.

2. Neisseria gonorrhoeae.

3. Streptococcus pneumoniae.

4. Streptococcus pyogenes.

1. Mycobacterium tuberculosis.

The “breath test” for Helicobacter pylori infection detects the presence of which of the following?

o) Antigens

a) Catalase

b) Hemolysis

c) Lactose fermentation

d) Urease

Urease

The “O157:H7” of E. coli O157:H7 refers to the

     o) biotype.

1. Serotype.

2. phage type.

3. antibiogram.

Serotype

When hydrogen peroxide is placed on a colony of an unknown bacterium, bubbles form. Based on this information, you can conclude that the bacterium

     o) is Staphylococcus epidermidis.

1. is a lactic acid bacterium.

2. is beta-hemolytic.

3. is catalase-positive.

4. can cause strep throat.

Is catalase-positive

Which of the following is best to use for determining the evolutionary relatedness of organisms?

      o) Ability to form endospores

1. 16S ribosomal RNA sequence

2. Sugar degradation

3. Motility

16S ribosomal RNA sequence

If the GC content of two organisms is 70%, the

o) organisms are definitely related.

a) organisms are definitely not related.

b) AT content is 30%.

c) organisms likely have extensive DNA homology.

d) organisms likely have many characteristics in common.

AT content is 30%

If two microbial isolates have similar but different 16S rRNA sequences, they are probably

    o) both motile.

1. both pathogens.

2. both cocci.

3. members of the same domain.

4. the same strain.

The same strain

The sequence of which ribosomal genes are most commonly used for establishing phylogenetic relatedness?

      o) 5S

1. 16S

2. 23S

3. All of these are commonly used.

16S

Which of the following is false?

     o) Tropheryma whipplei could be identified before it had been grown in culture.

1. The GC content of DNA can be measured by determining the temperature at which double-stranded DNA melts.

2. Sequence differences between organisms can be used to assess their relatedness.

3. Based on DNA homology studies, members of the genus Shigella should be in the same species as Escherichia coli.

4. The polymerase chain reaction (PCR) is used to determine the serotype of an organism.

1. The polymerase chain reaction (PCR) is used to determine the serotype of an organism

A catalase-negative colony growing on a plate that was incubated aerobically could be which of these genera?

     o) Bacillus

1. Escherichia

2. Micrococcus

3. Staphylococcus

4. Streptococcus

Streptococcus

All of the following genera are spirochetes except

      o) Borrelia.

1. Caulobacter.

2. Leptospira.

3. Spirochaeta.

4. Treponema

Caulobacter

If you examined the acidic runoff from a coal mine, which of the following would you most likely find growing there?

     o) Clostridium

1. Escherichia

2. Lactic acid bacteria

3. Thermus

4. Acidithiobacillus

Acidithiobacillus

The dormant forms of which set of genera or groups are the most resistant to environmental extremes?

     o) Azotobacter and Bacillus

1. Bacillus and Clostridium

2. Clostridium and myxobacteria

3. Myxobacteria and Streptomyces

4. Azotobacter and Streptomyces

Bacillus and Clostridium

If you read that coliforms had been found in a lake, the report could have been referring to which of the following genera?

     o) Bacteroides

1. Bifidobacterium

2. Clostridium

3. Escherichia

4. Streptococcus

Escherichia

Which of the following genera preys on other bacteria?

     o) Bdellovibrio

1. Caulobacter

2. Hyphomicrobium

3. Photobacterium

4. Sphaerotilus

Bdellovibrio

All of the following genera are obligate intracellular parasites except

     o) Chlamydia.

1. Coxiella.

2. Ehrlichia.

3. Mycoplasma.

4. Rickettsia.

Mycoplasma

All of the following genera fix nitrogen except

      o) Anabaena

1. Deinococcus

2. Azotobacter

3. Rhizobium

Deinococcus

Which of the following archaea would most likely be found coexisting with bacteria?

      o) Nanoarchaeum

1. Halobacterium

2. Methanococcus

3. Picrophilus

4. Sulfolobus

Picrophilus

Thermoplasma and Picrophilus grow best in which of the following extreme conditions?

     o) Low pH

1. High salt

2. High temperature

3. a and c

4. b and c

a and c

Cell walls of this group contain chitin.

             o) Algae

1. Protozoa

2. Fungi

3. Helminths

Fungi

Certain members of this group are the source of diatomaceous earth.

      o) Algae

1. Protozoa

2. Fungi

3. Helminths

Algae

Which of the following statements about fungi is false?

      o) Dimorphic fungi can transition between morphologies—usually molds and   yeasts.

1. Some fungi produce life-threatening toxins.

2. Fungal spores may cause allergic responses in humans.

3. Systemic mycoses are common in otherwise healthy adults.

1. Systemic mycoses are common in otherwise healthy adults.

Which of the following statements regarding protozoa is false?

       o) Intestinal amoebae are typically able to form cysts.

1. A defining characteristic of protozoa is the presence of mitochondria.

2. Some protozoa are parasitic.

3. Malaria is caused by a protozoan.

1. A defining characteristic of protozoa is the presence of mitochondria.

Which of the following is mismatched?

      o) Plasmodium—malaria

1. Trypanosomes—dysentery

2. Dinoflagellates—red tide

3. Nematode—trichinellosis

1. Trypanosomes—dysentery

The current phylogeny of eukaryotes is based upon 

      o) rRNA sequence comparisons.

1. possession of photosynthetic pigments.

2. mode of reproduction.

3. mode of locomotion.

Mode of reproduction

All algae 

     o) have chlorophyll a.

1. have cell walls that contain agar.

2. make holdfasts.

3. are multicellular.

have chlorophyll a.

Which of the following statements regarding protists is false?

      o) They include both autotrophic and heterotrophic organisms.

1. They include both microscopic and macroscopic organisms.

2. They are an intermediate host in schistosomiasis.

3. They include algae and protozoa.

  They are an intermediate host in schistosomiasis.

Which of the following statements regarding tapeworms is false?

      o) They absorb nutrients from the host through their body wall.

1. They complete their life cycles in a single host.

2. They are hermaphroditic.

3. They cannot be transmitted from human to human.

1. They cannot be transmitted from human to human.

Capsids are composed of

1. DNA.

2. RNA.

3. protein.

4. lipids.

5. polysaccharides.

Protein

The tail fibers on phages are associated with

1. attachment.

2. penetration.

3. transcription of phage DNA.

4. assembly of a virus.

5. lysis of the host.

attachment

Classification of viruses is based on all of the following except

1. type of nucleic acid.

2. shape of virus.

3. size of virus.

4. host infected.

5. strandedness of nucleic acid.

Size of virus

Temperate phages can do all of the following except

1. lyse their host cells.

2. change the properties of their hosts.

3. integrate their DNA into the host DNA.

4. bud from their host cells.

5. become prophages.

Bud from their host cells

All phages must be able to

1. inject their nucleic acid into a host cell.

2. kill the host cell.

3. multiply in the absence of living bacteria.

4. lyse the host cell.

5. have their nucleic acid replicate in the host cell.

1. 1, 2

2. 2, 3

3. 3, 4

4. 4, 5

5. 1, 5

1, 5

Filamentous phages

1. infect animal and bacterial cells.

2. cause their host cells to grow more quickly.

3. are extruded from the host cell.

4. undergo assembly in the cytoplasm.

5. degrade the host cells’ DNA.

are extruded from the host cell

Influenza vaccines must be changed yearly because the amino acid sequence of the viral proteins changes gradually over time. Based on this information, which is the most logical conclusion? The influenza virus

1. is enveloped.

2. is non-enveloped.

3. has a DNA genome.

4. has an RNA genome.

5. causes a persistent infection.

has an RNA genome

Acute infections of animals

1. are a result of productive infection.

2. generally lead to long-lasting immunity.

3. result from the integration of viral nucleic acid into the host.

4. are usually followed by chronic infections.

5. often lead to tumor formation.

1. 1, 2

2. 2, 3

3. 3, 4

4. 4, 5

5. 1, 5

1, 2

Determining viral titers of both phage and animal viruses frequently involves

1. plaque formation.

2. quantal assays.

3. hemagglutination.

4. determining the ID50.

5. counting of virions by microscopy.

Plaque formation

Prions

1. contain only nucleic acid without a protein coat.

2. replicate like HIV.

3. integrate their nucleic acid into the host genome.

4. cause diseases of humans.

5. cause diseases of plants

1. cause diseases of humans.

Which of the following is an example of a fomite?

1. Table

2. Flea

3. Staphylococcus aureus carrier

4. Water

5. Air

Table

Which of the following would be the easiest to eradicate?

1. A pathogen that is common in wild animals but sometimes infects humans

2. A disease that occurs exclusively in humans, always resulting in obvious symptoms

3. A mild disease of humans that often results in no obvious symptoms

4. A pathogen found in marine sediments

5. A pathogen that readily infects both wild animals and humans

1. A disease that occurs exclusively in humans, always resulting in obvious symptoms

Which of the following methods of disease transmission is the most difficult to control?

1. Airborne

2. Foodborne

3. Waterborne

4. Vector-borne

5. Direct person to person

Airborne

Which of the following statements is false?

1. A botulism epidemic that results from improperly canned green beans is an example of a common-source outbreak.

2. Droplet nuclei fall quickly to the ground.

3. Congenital syphilis is an example of a disease acquired through vertical transmission.

4. Plague is endemic in the rock squirrel population in parts of the United States.

5. The first case in an outbreak is called the index case.

1. Droplet nuclei fall quickly to the ground.

Which of the following statements is false?

1. A disease with a long incubation period might spread extensively before an epidemic is recognized.

2. A person exposed to a low dose of a pathogen might not develop disease.

3. The young and the aged are more likely to develop certain diseases.

4. Malnourished populations are more likely to develop certain diseases.

5. Herd immunity occurs when a population does not engage in a given behavior, such as eating raw fish, that would otherwise increase their risk of disease.

1. Herd immunity occurs when a population does not engage in a given behavior, such as eating raw fish, that would otherwise increase their risk of disease.

The purpose of an analytical study is to

1. identify the person, place, and time of an outbreak.

2. determine which potential risk factors result in high frequencies of disease.

3. assess the effectiveness of preventive measures.

4. determine the effectiveness of a placebo.

5. None of the above

1. determine which potential risk factors result in high frequencies of disease.

If you and your family all develop infectious diarrhea, the most likely portal of entry for the pathogen was the

1. large intestine.

2. mouth.

3. skin.

4. respiratory tract.

5. Nose.

Mouth

All of the following are thought to contribute to the emergence of disease except

1. advances in technology.

2. breakdown of public health infrastructure.

3. construction of dams.

4. mass distribution and importation of food.

5. widespread vaccination programs.

1. widespread vaccination programs.

Which of the following common causes of healthcare-associated infections is an environmental organism that grows readily in nutrient-poor solutions?

1. Enterococcus

2. Escherichia coli

3. Pseudomonas aeruginosa

4. Staphylococcus aureus

1. Pseudomonas aeruginosa

An endemic disease

1. is typically transmitted by asymptomatic carriers.

2. is more prevalent in the winter months than in the summer months.

3. requires transmission by a vector.

4. has been eradicated.

5. is always present at some level in a given population

1. is always present at some level in a given population