Microbes Exam 2 practice test attempt 2

A patient sample from an infected wound was cultured on medium containing high salt so that only halophilic organisms could grow. In addition, the medium contains mannitol (a sugar alcohol) and phenol red dye that indicates whether or not fermentation of mannitol has taken place by changing to a yellow color as the pH drops. This type of media would best be described as…

A. selective AND enrichment medium.

B. enrichment medium.

C. selective AND differential medium.

D. selective medium.

E. differential medium.

C. selective AND differential medium

Which of the following pH classifications would be able to grow in a pickle jar with vinegar?

A. acidophiles

B. neutralophiles

C. alkaliphiles

D. barophiles

E. psychrophiles

A. acidophiles

Nutrients that a cell needs to build new cells and make up a bulk of a cell's dry weight are called

A. tiny nutrients.

B. essential nutrients.

C. small nutrients.

D. micronutrients.

E. trace nutrients.

B. essential nutrients

An unknown organism is being tested for the ability to ferment various sugars. The pH indicator phenol red is added to a fermentation broth containing sucrose. Phenol red indicator is pink at a pH above 8, red at pH 7, and yellow at a pH below 7. After incubation, if the organism can ferment sucrose, what color will the fermentation broth be?

A. Yellow, because fermentation of sucrose will result in the production of acidic products.

B. Pink, because fermentation of sucrose will result in the production of basic products.

C. Yellow, because fermentation of sucrose will result in the production of basic products.

D. Red, because fermentation of sucrose will result in a neutral pH.

E. Red, because fermentation of sucrose will produce acidic products.

A. Yellow, because fermentation of sucrose will result in the production of acidic products.

When electrons are removed from nutrients via an oxidation reaction, the coupled reduction reaction may be

A. NAD → NADH.

B. FAD → FADH2.

C. NADH → NAD+.

D. either FAD → FADH2 or NAD+ → NADH.

E. either NAD+ → NADH or NADH → NAD+.

D. either FAD → FADH2 or NAD+ → NADH.

Which molecule is the main product of the intermediate step that enters the Krebs cycle?

A. carbon dioxide

B. acetyl CoA

C. NAD+

D. ATP

E. pyruvic acid

B. acetyl CoA

Many strains of E. coli are able to grow on minimal media which consists only of a single sugar, usually glucose, and inorganic salts to provide nitrogen, sulfur, phosphorous and trace nutrients. What does this tell you about E. coli's biosynthetic capabilities?

A. All amino acids are "essential" to E. coli.

B. E. coli will use salvage pathways to make nucleotides.

C. E. coli can funnel intermediates from glycolysis, the intermediate step, and the Krebs cycle to synthesize amino acids, fatty acids, glycerol, and nucleotides.

D. E. coli will be unable to perform amination.

E. E. coli will be unable to build the peptidoglycan it needs for its cell wall.

C. E. coli can funnel intermediates from glycolysis, the intermediate step, and the Krebs cycle to synthesize amino acids, fatty acids, glycerol, and nucleotides.

Which of the following is an indirect infectious disease transmission mode?

A. vertical

B. environment

C. vehicle

D. person to person

E. animal

C. vehicle

What are the three factors of the epidemiological triangle?

A. time from exposure to symptoms, access to transportation, quality of hospitals

B. vaccine use, disinfectant use, and hand-washing policy

C. environmental factors, etiological agent, and host factors

D. pathogen type, host health, and geographic overlap

E. survivability, length of acute phase, cultural factors

C. environmental factors, etiological agent, and host factors

How is a reemerging pathogen different from an emerging pathogen?

A. A reemerging pathogen is an infectious bacterial infection that manifests once every few months but goes away without treatment and only blisters the skin in another few months.

B. A reemerging pathogen is an infectious helminth that was detected in one location of the body but receded and emerged from a second location.

C. A reemerging pathogen is an infectious agent that was under control due to prevention or treatment strategies and is now resurfacing.

D. A reemerging pathogen is an infectious agent that went away when the patient was taking antibiotics but quickly returned when the patient stopped taking the antibiotics.

E. A reemerging pathogen is an infectious agent that was identified previously in one location but is now emerging in a new separate location.

C. A reemerging pathogen is an infectious agent that was under control due to prevention or treatment strategies and is now resurfacing.

Animal viruses can be grown in all of the following except

A. tissue culture.

B. E. coli cells.

C. live animal hosts.

D. embryonated eggs.

E. HeLa cells.

B. E. coli cells.

Phage conversion occurs when

A. prophage confer new pathogenic properties on bacterial cells.

B. bacteriophage are used clinically to treat bacterial infections.

C. a host cell is infected by a bacteriophage.

D. prophase excise themselves and resume lytic replication when the host cell is stressed.

E. bacteriophage are released from the host cell.

A. prophage confer new pathogenic properties on bacterial cells

Oncogenic viruses

A. are never RNA viruses.

B. increase host cell responsiveness to death signals.

C. are never maintained episomally.

D. stimulate uncontrolled host cell division.

E. always integrate into the host cell DNA.

D. stimulate uncontrolled host cell division.

Examples of healthy host-microbe interactions with our normal microbiota include all except

A. competition with pathogens.

B. vitamin manufacture.

C. microbiota disruption.

D. moderation of immune attack against microbiota species while in their normal tissues.

E. immune system maturation.

C. microbiota disruption.

Which mode of transmission is not addressed by transmission precautions?

A. airborne

B. vector

C. droplet

D. airborne and droplet

E. direct contact

B. vector

The degree or extent of disease that a pathogen causes is

A. attenuation.

B. virulence.

C. a host factor.

D. toxicity.

E. pathogenicity.

B. virulence

Properties that contribute to virulence

A. are determined by both the microbe and the host, and are fixed and unchanging.

B. are determined by both the microbe and the host, and may evolve over time.

C. are determined solely by the microbe.

D. are determined solely by the host.

E. are fixed and unchanging.

B. are determined by both the microbe and the host, and may evolve over time.

Septic shock is typically associated with

A. exotoxins.

B. superantigens.

C. exotoxins or endotoxin.

D. either Gram-negative or Gram-positive infections.

E. Gram-negative infections.

E. Gram-negative infections.

Which of the following infectious disease transmission modes is not correctly paired with an example?

A. windborne: cholera

B. flea bite: Plague

C. touching: cat-scratch fever

D. breast milk: HIV

E. swimming: swimmer's ear

A. windborne: cholera

Viruses which infect many different tissues types are said to have a(n)

A. broad host range.

B. indeterminate host range.

C. narrow tropism.

D. broad tropism.

E. narrow host range.

D. broad tropism.

A chemical used to control microbial growth on inanimate objects is called a(n)

A. disinfectant.

B. antiseptic.

C. antibacterial agent.

D. microbiostatic.

E. microbiocidal.

A. disinfectant.

Which of the following pathways are operational in a cell growing via fermentation?

A. glycolysis and intermediate step only

B. glycolysis, intermediate step, and the Krebs cycle

C. glycolysis

D. intermediate step

E. Krebs cycle

C. glycolysis

Endemic infections

A. are routinely detected in a population or region.

B. are infections that have only been recorded within the past 1,000 years and not before.

C. are infections that are life threatening if not treated in a timely manner.

D. are isolated infections in a particular population.

E. are infections that are expected to be cured and wiped out by the year 2050.

A. are routinely detected in a population or region.

It is called a ________ vector when the vector has a role in the pathogen's life cycle.

A fomite

B. zoonotic

C. biological

D. vehicle

E. mechanical

C. biological

Which of the following does not help to limit the spread of healthcare-acquired infections?

A.dedicating equipment for a single patient's use whenever possible (a blood pressure cuff)

B. transporting patients as often as possible to keep the healthy patients away from the sick patients

C. environmental sanitization and equipment sterilization

D. proper hand washing even if gloves will be worn

E. consistent use of personal protective wear (gloves, masks, and gowns)

B. transporting patients as often as possible to keep the healthy patients away from the sick patients

Which factors may result in a normal microbiota species causing disease?

A. dysbiosis due to antibiotic therapy or immune system attack on the host's own tissue

B. dysbiosis due to antibiotic therapy or invasion of other tissues by the microbiota species

C. immune system attack on the host's own tissues

D. dysbiosis due to antibiotic therapy

E. invasion of other tissues by the microbiota species

B. dysbiosis due to antibiotic therapy or invasion of other tissues by the microbiota species

ID50 describes

A. the number of cells or virions needed to establish an infection in 50 percent of exposed hosts.

B. the percentage of individuals which will develop an infection after exposure to 50 cells or virions.

C. the number of cells or virions which will kill 50% of exposed hosts.

D. the number of cells or virions which will kill 50 individuals.

E. the amount of toxin lethal to a 50-pound human or other animal.

A. the number of cells or virions needed to establish an infection in 50 percent of exposed hosts.

Which of the following is not a way that pathogens can avoid destruction by the phagocytes of the host immune system?

A. make a capsule which is toxic to the phagocyte

B. adapt to living inside the phagocyte

C. block fusion of the phagosome with the lysosome inside the phagocyte

D. neutralize the hydrolytic enzymes produced by the phagocyte

E. release toxins which kill the phagocyte

A. make a capsule which is toxic to the phagocyte

Which of the following is not a hallmark sign of infections in patients with primary immunodeficiencies?

A. persistent

B. severe

C. acute

D. caused by uncommon agents

E. recurring

C. acute

Which of the following is not a drawback of live attenuated vaccines?

A. They may mutate back to a pathogenic form.

B. They may cause secondary transmission from an immunized person to another host.

C. They are quickly cleared from the body, limiting antigen exposure.

D. They generally must be refrigerated until they are administered, limiting their use in developing countries.

E. They may cause disease in immunocompromised hosts.

C. They are quickly cleared from the body, limiting antigen exposure.

Which statement is not true about chronic persistent viral infections?

A. A period of quiet infection where the host is asymptomatic is followed by a period of active viral replication

B. The immune system fails to clear the infection

C. May involve periods of flare-up where the virus is actively replicating alternating with periods of dormancy

D. Small numbers of virions may be produced and released from host cells during the quiet periods

E. May involve integration of the virus into the host cell DNA to form a provirus.

C. May involve periods of flare-up where the virus is actively replicating alternating with periods of dormancy

The minimum temperature needed to kill all microbes in a sample within ten minutes is called the

A. thermal death point

B. critical death time

C. decimal reduction time

D. essential reduction point.

E. thermal death time.

A. thermal death point

Which of the following methods would surgical staff use to disinfect surfaces in operating rooms?

A. autoclaving

B. gamma ray radiation

C. x-ray radiation

D. non-ionizing radiation

E. ionizing radiation

D. non-ionizing radiation

Which of the products of the Krebs cycle provide the main energy benefit in terms of ATP production in the electron transport chain?

A. CO2

B. Acetyl-CoA

C. ADP and GDP

D. citric acid

E. NADH and FADH2

E. NADH and FADH2

Which of the following statements is not correct with respect to healthcare-acquired infections?

A. Healthcare-acquired infections may also occur outside of a healthcare facility during administration of professional home health care.

B. Healthcare-acquired infections add an extra $10 billion dollars per year to U.S. healthcare costs.

C. Hospitals have been inadvertent sources of infection for thousands of years.

D. About 75,000 people die from healthcare-acquired infections every year.

E. Due to the installation of hand sanitizing dispensers in hospitals, healthcare-acquired infections decreased significantly in the past several years.

E. Due to the installation of hand sanitizing dispensers in hospitals, healthcare-acquired infections decreased significantly in the past several years.

Which of the following is not a goal of the public health system?

A. diagnoses

B. prevents

C. works to reduce health problems in the community

D. investigates

E. designs treatments, cures, or vaccines

E. designs treatments, cures, or vaccines

An attenuated pathogen

A. has recently acquired virulence factors allowing it to jump species.

B. has become antibiotic-resistant.

C. produces toxins

D. has lost virulence factors needed to cause disease in an immune competent host.

E. is part of the normal human microbiome.

D. has lost virulence factors needed to cause disease in an immune competent host.

Which method of hiding from the host immune system is incorrectly matched with its description?

A. living intracellularly: a pathogen resides on the surface of a host cell where it is hidden by host cell surface molecules

B. antigen mimicry: the pathogen's antigens are similar in structure to host molecules

C. antigen variation: the pathogen frequently switches its antigens

D. latency: a pathogen exists quietly inside the host cell

E. antigen masking: the pathogen covers itself in host factors to avoid detection of its own antigens

A. living intracellularly: a pathogen resides on the surface of a host cell where it is hidden by host cell surface molecules

A water treatment plant is testing for E. coli and other coliforms using Eosin-Methylene blue (EMB) media that will produce metallic green colonies in the presence of coliform bacteria. After performing serial dilutions and spread-plating 1 ml of each of the dilutions on the EMB, the 1:1000 dilution plate produced 130 total colonies, with 85 metallic green colonies. How many coliforms (in CFU/ml) were in the original water sample?

A. 85 CFU/ml

B. 130,000 CFU/ml

C. 130 CFU/ml

D. 8,500 CFU/ml

E. 85, 000 CFU/ml

E. 85, 000 CFU/ml

What is the definition of a true pathogen?

A. needs to passed from one person to the next

B. must be a bacterial or viral pathogen

C. must cause diarrhea, vomiting, and fever in the patient

D. does not require a weakened host to cause disease

E. causes disease within one week of infecting the patient

D. does not require a weakened host to cause disease