MCB100 EXAM 2 HW QUESTIONS
Based on its Gram status, why are penicillin and other beta-lactam antibiotics effective against Streptococcus pneumoniae? Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and does not have an outer membrane. Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and has an outer membrane. Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram negative organism and has an outer membrane. Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram negative organism and does not have an outer membrane.
Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and does not have an outer membrane.
The host DNA is usually degraded during which stage? Release Penetration Attachment Biosynthesis Assembly
Biosynthesis
How do blastoconidia and chlamydoconidia produced by yeast differ from bacterial endospores? Blastoconidida and chlamydoconidia are identical to endospores. Blastoconidia and chlamydoconidia are produced only by yeasts in extreme conditions, whereas bacterial endospores are asexual reproductive structures. Blastoconidia and chlamydoconidia are male and female mating structures used for reproduction in yeasts, whereas bacterial endospores are asexual reproductive structures. Blastoconidia and chlamydoconidia are spore structures produced by budding in yeasts, whereas bacterial endospores are produced by bacteria under extreme conditions.
Blastoconidia and chlamydoconidia are spore structures produced by budding in yeasts, whereas bacterial endospores are produced by bacteria under extreme conditions.
Why are doxycycline and rifampin ideal agents for treating intracellular pathogens such as Brucella and Mycobacteria? Both agents act synergistically in producing a bactericidal effect. Both agents interfere with the protein synthesis of intracellular pathogens. Both agents provide for good penetration of body tissues and reach therapeutic levels. Both agents interfere with mRNA synthesis.
Both agents provide for good penetration of body tissues and reach therapeutic levels.
The pathology of cepacia syndrome is often complex and due to multiple factors. All of the following factors may contribute to the development of cepacia syndrome EXCEPT which one? The severity of Burkholderia cepacia infection is due in part to the microbes' ability to form biofilms, which are resistant to penetration by antimicrobials. The defective CFTR protein leads to increased mucus and viscosity, which allow the organism to persist. The patient's clinical status does not improve, and progressive respiratory impairment and failure follow. Patients who are colonized and/or infected with Burkholderia cepacia genomovar III are most likely to develop cepacia syndrome. Burkholderia cepacia produces an inducible beta-lactamase.
Burkholderia cepacia produces an inducible beta-lactamase.
Which opportunistic fungus is characterized by pseudohyphae? Pneumocystis Histoplasma Aspergillus Candida
Candida
In which stage is the viral DNA introduced into the cell? Penetration Release Attachment Assembly Biosynthesis
Penetration
Which of the following is multicellular, chemoheterotrophic, and has a cell wall? Plasmodium Histoplasma Cryptosporidium Giardia
Histoplasma
What is the fate of the prophage during the lysogenic stage? It is released from the cell by lysing the cell. It is packaged into viral proteins and maintained until the host is exposed to an environmental stress. It is degraded by the activity of host defense enzymes. It is copied every time the host DNA replicates.
It is copied every time the host DNA replicates.
Why is necrotizing fasciitis so difficult to prevent? It is not susceptible to most antibiotics. Mosquitos are almost impossible to eradicate. It forms endospores and can survive well in the environment. It is part of the normal microbiota.
It is part of the normal microbiota.
Which of the following best describes the role of sebum as a component of the first line of defense? Select all that apply. Sebum forms a protective layer over the skin. Sebum helps to keep the pH of the skin low, which inhibits the growth of microorganisms. Sebum contains enzymes that inhibit the growth of pathogens. Sebum creates an anaerobic environment, thereby preventing the growth of pathogenic organisms.
Sebum forms a protective layer over the skin. Sebum helps to keep the pH of the skin low, which inhibits the growth of microorganisms.
Further testing reveals this is a strain of E. coli O157:H7. What virulence factor produced by this strain could cause the heart and lung damage observed in this case? endospores enterotoxin flagella Shiga-like toxin
Shiga-like toxin
Further testing reveals this is a strain of E. coli O157:H7. What virulence factor produced by this strain could cause the heart and lung damage observed in this case? flagella Shiga-like toxin endospores enterotoxin
Shiga-like toxin
What are flexible, spiral-shaped bacteria called? Bacilli Pleomorphic Spirochetes Spirilla
Spirochetes
What type of arrangement forms when multiple planes of division occur randomly in cocci? Tetrads Staphylococci Diplococci Streptococci
Staphylococci
What is the "gold standard" for treatment of histoplasmosis? 5-fluorocytosine clotrimazole amphotericin B griseofulvin
amphotericin B
Lysogeny is associated with all of the following EXCEPT __________. animal viruses bacteriophages increasing virulence of host bacterium a prophage
animal viruses
MDR-TB is more problematic in a hospital than "regular" tuberculosis because MDR-TB is a dormant infection acid fast antibiotic resistant medical doctor related (meaning that it is acquired from medical staff)
antibiotic resistant
During viral replication, before a virus enters its host cell, it must first fuse with a host cell's membrane. synthesize. attach. uncoat.
attach.
A phage T4 particle that has lost its tail fibers will have a replication cycle that is blocked at which of the following stages? attachment entry assembly synthesis
attachment
A(n) ________ is a virus that infects bacterial cells. envelope prion bacteriophage nucleocapsid virion
bacteriophage
The outermost layer of a virion fulfills which of the following functions of the virus? protection recognition replication both protection and recognition both recognition and replication
both protection and recognition
In which of the following methods of prokaryotic reproduction does the parental cell remain intact after the reproduction event to continue the process? budding binary fission binary fission and snapping division snapping division
budding
Although many people along the Mississippi, Missouri and Ohio River valleys have been exposed and test positive for histoplasmosis, most (95%) are asymptomatic. How do they clear the organism from their bodies? Specific antibodies are produced in response to antigens on the pathogen and the fungus is neutralized. The organism is cleared from their body in urine. The organism is cleared from their body by coughing. cell-mediated immunity
cell-mediated immunity
A retrovirus has ____________ for its genome; these viruses carry the enzyme reverse transcriptase to transform their genetic code into dsDNA. dsRNA ssDNA −ssRNA +ssRNA
+ssRNA
Which of the following habits will best prevent infection due to listerosis? Avoid hard cheeses, such as cheddar. Avoid eating or drinking pasteurized dairy products. Avoid eating raw fruits and vegetables Wash your hands after handling pet feces.
Avoid eating raw fruits and vegetables
Which of the following cells is NOT infected by HIV? microglia macrophages helper T cells dendritic cells B lymphocytes
B lymphocytes
What percent of patients are estimated to die from the disease? View Available Hint(s) 0% 20% 100% 75%
20%
It is estimated that _____ of the world's population may be infected with tuberculosis. 75% 33% 1% 5%
33%
What is the difference between the cell walls of Gram-positive bacteria and those of Gram-negative bacteria? A Gram-positive bacterium has lipid A embedded in its cell wall. A Gram-positive bacterium has a cell wall in which chains of amino acids are linked together by groups of four sugars, while Gram-negative bacteria have chains of sugars linked together by groups of amino acids. A Gram-positive bacterium has a periplasmic space between an inner and an outer membrane. A Gram-positive bacterium has a thick layer of peptidoglycan and lacks an outer membrane.
A Gram-positive bacterium has a thick layer of peptidoglycan and lacks an outer membrane.
Which is the vector of Rickettsia rickettsia? A cockroach A flea A tick A biting fly
A tick
Rickettsia rickettsii is a gram-negative, obligate intracellular pathogen. Which of the following statements about the R. rickettsii life cycle is FALSE? Like viruses, R. rickettsii requires a eukaryotic host in order to carry out its life cycle. In order to cause RMSF, R. rickettsii must enter host cells. After entering a host, R. rickettsii multiplies to levels high enough to successfully invade cells and establish an infection. During infection, R. rickettsii is able to survive and replicate within eukaryotic cells.
After entering a host, R. rickettsii multiplies to levels high enough to successfully invade cells and establish an infection.
What is listeriolysin O? An enzyme breaks the bacteria free from the phagosome. An enzyme that destroys the cell membrane, leading to cell death. A toxin that paralyzes cell activity. A protein that binds to actin filaments.
An enzyme breaks the bacteria free from the phagosome.
In the case of gastrointestinal disease, how can an intoxication be distinguished from an infection?Part complete An intoxication is usually apparent shortly after ingestion, while an infection takes longer. Infections are caused by heat-stable agents. An intoxication usually causes a fever, while an infection does not. Intoxications may be caused by endotoxin.
An intoxication is usually apparent shortly after ingestion, while an infection takes longer.
Although cholera can be treated with antibiotics, data suggest that antibiotic treatment alone is NOT the most effective therapy. Which of the following statements describes the most likely reason for supplementing antibiotic therapy? The production of cholera toxin helps V. cholerae resist antibiotic treatment. Antibiotic therapy addresses only the growth of V. cholerae; it doesn't address the extreme dehydration suffered by a person infected with V. cholerae. As with V. cholerae, the acidic environment of the stomach can have a negative impact on antibiotic activity. Because V. cholerae is a gram-negative organism, it is not very effectively treated with antibiotics.
Antibiotic therapy addresses only the growth of V. cholerae; it doesn't address the extreme dehydration suffered by a person infected with V. cholerae.
Why are antimicrobial drugs of limited usefulness in Bacillus anthracis infections? Most strains of B. anthracis are resistant to a wide variety of antimicrobial drugs. B. anthracis grows so slowly that it is hard to kill using antimicrobial drugs. Antimicrobial drugs are unable to neutralize anthrax toxin. Anthrax toxin is absorbed into the bloodstream very quickly.
Antimicrobial drugs are unable to neutralize anthrax toxin.
Choose the characteristics that separate the archaea from other prokaryotic cells. A. The morphology of the cell is rigid and is geometric in shape, similar to a sphere or cylinder. B. All currently identified and characterized archaea have been linked as the causative agent to an animal or human disease. C. Archaea lack true peptidoglycan in their cell walls. D. The cytoplasmic membrane lipids of archaea have branched or ringform hydrocarbon chains.
Archaea lack true peptidoglycan in their cell walls. The cytoplasmic membrane lipids of archaea have branched or ringform hydrocarbon chains.
In which stage does formation of mature viruses occur? Biosynthesis Penetration Attachment Assembly Release
Assembly
What is the name of the vaccine given to prevent TB in countries where it is endemic? BCG vaccine DTaP vaccine Pneumovax vaccine RTS vaccine
BCG vaccine
What type of organisms do phages infect? Animals Bacteria Protozoa Plants
Bacteria
How does coagulase facilitate bacterial virulence? Bacteria can hide in the protein clots that result from the action of coagulase. Coagulase breaks down blood clots in which bacteria hide, releasing them so they can spread to other parts of the body. Coagulase breaks down the material that allows neighboring cells to adhere to each other. Coagulase breaks down an important structural protein in the body.
Bacteria can hide in the protein clots that result from the action of coagulase.
Name a structural difference between animal viruses and bacteriophages. Animal viruses may be enveloped; bacteriophages are always naked. Bacteriophages have glycoprotein spikes, while animal viruses do not. The capsid of animal viruses enters the host cell, while those of bacteriophages stay outside the host cell. Animal viruses may have tails or tail fibers, while bacteriophages do not.
Bacteriophages have glycoprotein spikes, while animal viruses do not.
Gram-negative bacteria in the genus ________ prey on other Gram-negative bacteria. Mycoplasma Rickettsia Caulobacter Chlamydia Bdellovibrio
Bdellovibrio
A patient infected with a protozoan parasite who also exhibits congestive heart failure is most likely in the final stages of which of the following diseases? trichomoniasis giardiasis Chagas' disease leishmaniasis
Chagas' disease
Which of the following habits might best prevent infection with Candida? Take vitamin C supplements. Change wet diapers often. Irrigation of the vaginal cavity daily with a douching agent. Use condoms during sexual intercourse.
Change wet diapers often.
How are patients typically infected with listeriosis? A tick bite Inhalation of dust particles Contaminated food or drink Eating undercooked chicken
Contaminated food or drink
Why were corticosteroids contraindicated in this case? Corticosteroids produce bronchoconstriction. Corticosteroids increase the permeability of blood vessels, causing tissue swelling. Corticosteroids are a type of antibiotic. Corticosteroids are immunosuppressive.
Corticosteroids are immunosuppressive.
Why were corticosteroids contraindicated in this case? Corticosteroids increase the permeability of blood vessels, causing tissue swelling. Corticosteroids are immunosuppressive. Corticosteroids produce bronchoconstriction. Corticosteroids are a type of antibiotic.
Corticosteroids are immunosuppressive.
How might an infected patient transmit listeriosis to another human? Through sexual contact. During pregnancy. Aerosolized droplets in a cough. Fecal-oral route.
During pregnancy.
Which of the following tests would be useful in identifying Escherichia coli? E. coli is a Gram-negative bacillus that ferments glucose and sucrose, but not lactose. It is motile and does not utilize citrate or urea. E. coli is a Gram-negative diplococcus that ferments lactose and glucose, but not sucrose. It is motile and breaks down citrate. It cannot produce urease. E. coli is a Gram-negative bacillus that ferments glucose and sucrose, but not lactose. It is nonmotile and can produce urease, but it does not utilize citrate. E. coli is a Gram-negative bacillus that ferments lactose and glucose, but not sucrose. It is motile and does not utilize citrate or urea.
E. coli is a Gram-negative bacillus that ferments lactose and glucose, but not sucrose. It is motile and does not utilize citrate or urea.
Which of the following tests would be useful in identifying Escherichia coli? E. coli is a Gram-negative bacillus that ferments glucose and sucrose, but not lactose. It is nonmotile and can produce urease, but it does not utilize citrate. E. coli is a Gram-negative bacillus that ferments lactose and glucose, but not sucrose. It is motile and does not utilize citrate or urea. E. coli is a Gram-negative diplococcus that ferments lactose and glucose, but not sucrose. It is motile and breaks down citrate. It cannot produce urease. E. coli is a Gram-negative bacillus that ferments glucose and sucrose, but not lactose. It is motile and does not utilize citrate or urea.
E. coli is a Gram-negative bacillus that ferments lactose and glucose, but not sucrose. It is motile and does not utilize citrate or urea.
Choose from the following statements the ones that correctly discuss reproduction using binary fission in a bacterial cell. A. Each daughter cell is an exact copy of the other, both genetically and morphologically. B. Due to the stretching of the cytoplasmic membrane, both cells will contain a complete genome. C. The daughter cell will be a permanently smaller copy of the mother cell but will contain a complete genome. D. Each daughter cell will contain an equal number of organelles.
Each daughter cell is an exact copy of the other, both genetically and morphologically. Due to the stretching of the cytoplasmic membrane, both cells will contain a complete genome
What is empyema? Empyema refers to blood in the pleural cavity. Septicemia refers to a pocket of pus in between the lung and the inner surface of the chest wall. Empyema refers to a pocket of pus in between the lung and the inner surface of the chest wall. Empyema refers to air in the pleural cavity.
Empyema refers to a pocket of pus in between the lung and the inner surface of the chest wall.
Which of the following correctly describes the function of bacterial endospores? Endospores are reproductive structures produced by some Gram-positive bacteria. Endospores are specialized reproductive cells produced by chlamydias. Endospores are specialized cells used for nitrogen fixation. Endospores are produced as resting stages of the bacterium that can survive inhospitable conditions.
Endospores are produced as resting stages of the bacterium that can survive inhospitable conditions.
What is the function of endospores? Endospores are storage sites inside bacteria where excess nutrients are stored. Endospores are sites of protein synthesis inside bacterial cells. Endospores are reproductive structures that produce numerous offspring for a bacterium. Endospores are survival structures.
Endospores are survival structures.
Into which type of cell are the Rickettsia introduced in the human host? Liver cells Endothelial cells Kidney cells Skin cells
Endothelial cells
The organism isolated from the sprouts is oxidase negative, motile, ferments glucose and lactose, and cannot utilize citrate. What organism is it? Salmonella enterica Enterobacter aerogenes Shigella sonnei Escherichia coli
Escherichia coli
What is the best way to prevent nosocomial MRSA infections? All hospitalized patients should take antibiotics daily. Everyone should wash their hands before eating and after contact with any potentially contaminated surface/person. All hospitalized patients should wear a surgical mask People should be vaccinated with the MRSA vaccine.
Everyone should wash their hands before eating and after contact with any potentially contaminated surface/person.
Which of the following events might trigger induction of a temperate bacteriophage? Bacterial conjugation An infected cell entering the logarithmic phase of growth Exposure to UV light Normal cell division of an infected cell
Exposure to UV light
Most microbes that reside in the intestines are facultative or obligate anaerobes. Describe the growth of facultative anaerobes in the presence of and also in the absence of molecular oxygen.Part complete Facultative anaerobes grow equally well in the presence of and in the absence of molecular oxygen. Facultative anaerobes require the absence of molecular oxygen. Facultative anaerobes can grow without molecular oxygen, but grow faster in its presence. Facultative anaerobes require a small amount of molecular oxygen.
Facultative anaerobes can grow without molecular oxygen, but grow faster in its presence.
Contact with infected cats and their feces is the only mode of transmission of Toxoplasma to humans. True False
False
Plasmodium reproduces by binary fission. True False
False
What is the primary source of infection for UTIs? Contaminated drinking water Sexual intercourse Dehydration Fecal contamination
Fecal contamination
Which of the following statements about fermentative metabolism is true? Fermentation is unfavorable because the production of acidic end-products provides an unfavorable environment for the organism's growth. Fermentation does not yield any ATP for the cell. Fermentation produces significantly less ATP than aerobic respiration; however it generates NAD+, which can be used in glycolysis. All fermentative organisms have the ability to perform ethanol fermentation.
Fermentation produces significantly less ATP than aerobic respiration; however it generates NAD+, which can be used in glycolysis.
A subset of select agents and toxins have been designated as Tier 1 because these biological agents and toxins present the greatest risk of deliberate misuse with significant potential for mass casualties or devastating effect to the economy, critical infrastructure, or public confidence. They also pose a severe threat to public health and safety. Why is Francisella tularensis considered a select agent? Francisella tularensis is an intracellular parasite. Francisella tularensis can penetrate unbroken skin. Disease can result from as few as 10 organisms and there are many different modes of transmission. Francisella tularensis is Gram-negative and produces endotoxin. Francisella tularensis can produce endospores.
Francisella tularensis can penetrate unbroken skin. Disease can result from as few as 10 organisms and there are many different modes of transmission.
Which of the following statements best describes why the treatment for Tori's fungal infection may result in side effects to her own cells? Fungal cells and human cells both reproduce via budding. Fungal cells and human host cells both have cell walls made of cellulose. Fungal cells and human cells have a nucleus, multiple organelles, and 80S ribosomes for protein synthesis. Fungal cells and human host cells both have flagella for movement.
Fungal cells and human cells have a nucleus, multiple organelles, and 80S ribosomes for protein synthesis.
How are fungal and animal cytoplasmic membranes different from each other? Animal cytoplasmic membranes contain ergosterol, while fungal cytoplasmic membranes contain chitin and glucan. Animal cytoplasmic membranes contain cholesterol, while fungal cytoplasmic membranes do not contain any sterols. Fungal cytoplasmic membranes contain ergosterol, while animal cytoplasmic membranes contain cholesterol. Animal cytoplasmic membranes contain cholesterol, while fungal cytoplasmic membranes contain chitin and glucan.
Fungal cytoplasmic membranes contain ergosterol, while animal cytoplasmic membranes contain cholesterol.
What is the difference between fungal spores and bacterial endospores? Fungal spores are very hardy and more capable of withstanding extreme circumstances than bacterial endospores. Fungal spores are survival structures, while bacterial endospores are reproductive structures. Fungal spores are reproductive structures, while bacterial endospores are survival structures. Fungal spores spread by wind and are therefore smaller than bacterial endospores.
Fungal spores are reproductive structures, while bacterial endospores are survival structures.
What are dimorphic fungi? Fungi that can form different types of asexual spores Fungi that produce asexual spores and sexual spores Fungi that produce both aseptate and septate hyphae Fungi that can exist in yeast form and mold form
Fungi that can exist in yeast form and mold form
What is the difference between Gram-positive bacteria and mycoplasmas? Mycoplasmas have a thick layer of mycolic acid. Gram-positive bacteria have thick cell walls, while mycoplasmas lack cell walls. Gram-positive bacteria have sterols in their cytoplasmic membrane, while mycoplasmas do not. Gram-positive bacteria have cell walls made up of peptidoglycan, while mycoplasmas have glucan in their cell walls.
Gram-positive bacteria have thick cell walls, while mycoplasmas lack cell walls.
Streptococcus pneumoniae is found as part of the normal microbiota of the mouth and pharynx and yet can cause disease in some people when it is inhaled into lungs. Why do you think this is? The environment in the lungs is more favorable for Streptococcus pneumoniae than the nasopharynx. If Streptococcus pneumoniae is inhaled from the nasopharynx into lungs damaged by a previous viral infection or in an immune compromised person, it can flourish. If Streptococcus pneumoniae is inhaled deeply enough into the lungs, there are receptors present to which the bacteria can adhere. There is less immune system surveillance in the lungs compared to the nasopharynx.
If Streptococcus pneumoniae is inhaled from the nasopharynx into lungs damaged by a previous viral infection or in an immune compromised person, it can flourish.
Which of the following is a method by which viruses can enter animal cells? Induced endocytosis Exocytosis Uncoating Budding
Induced endocytosis
The pneumococcal vaccine was made using the purified capsular material from 23 common strains of Streptococcus pneumoniae, but it is not effective against all strains. Why is this? It cannot cover all the strains of Streptococcus pneumoniae because not all strains have the same antigens on their surface. It cannot cover all the strains of Streptococcus pneumoniae because not all strains have the same type of cell wall. If a person is infected with a strain other than the 23 used to make the vaccine, it may not be recognized by neutrophils. If a person is infected with a strain other than the 23 used to make the vaccine, it may not be recognized by the natural killer (NK) cells of the immune system.
It cannot cover all the strains of Streptococcus pneumoniae because not all strains have the same antigens on their surface.
Which of the following bacterial genera includes species that protect areas of the body such as the intestinal tract and the vagina from invasion by pathogens? Listeria Mycobacterium Lactobacillus Staphylococcus Corynebacterium
Lactobacillus
How is latency of animal viruses different from lysogeny of phages? Latency involves RNA viruses; lysogeny involves DNA viruses. Latency involves enveloped viruses, while lysogeny does not. Latent viruses emerge from the cell by lysis; lysogenic viruses bud from the cell. Animal viruses are not induced or excised from the host's DNA.
Latent viruses emerge from the cell by lysis; lysogenic viruses bud from the cell.
What might a clinician expect to observe in the urinalysis of a patient with a UTI? Epithelial cells Crystals Leukocytes Dark urine
Leukocytes
The signs of opportunistic HAI's with Gram-negative bacteria typically include high fever, inflammation, tissue edema, low blood pressure and DIC. What common structural characteristic of Gram-negative bacteria is directly or indirectly responsible for these signs? Flagellin Lipid A Phospholipid Peptidoglycan Fimbriae
Lipid A
Which component of a Gram-negative cell wall can cause fever, vasodilation, inflammation, shock, and blood clotting?Part complete Lipid A The periplasm The inner membrane Peptidoglycan
Lipid A
Which of the following occurs only in Gram-negative bacteria? Lipopolysaccharide Integral proteins Phospholipids Lipoteichoic acid Peptidoglycan
Lipopolysaccharide
How are lysogenic phages different from lytic phages? Lytic phages can change the phenotype of a bacterium, while lysogenic phages do not. Lytic phages prevent reinfection of their host bacterium by the same type of phage, while lysogenic phages do not. Lysogenic phages have dsDNA genomes, while lytic phages have ssRNA genomes. The genome of a lysogenic phage is integrated into its host genome.
Lytic phages can change the phenotype of a bacterium, while lysogenic phages do not.
__________ is an antiphagocytic factor and helps S. pyogenes attach to nose and throat cells. Deoxyribonuclease M protein Hyaluronidase Streptolysin
M protein
Using a mouse model, the investigator orally inoculates mice with a mutated strain of Brucella lacking the gene for production of urease. Indicate which of the following would LEAST support the hypothesis that urease plays a role as a virulence factor in establishing Brucella infection. Mice infected with mutated Brucella will NOT demonstrate inhibition of phagosome acidification by ammonia. Mutant and nonmutant strains will demonstrate the ability to transition through intestinal mucosa. Counts of viable mutant strains from the upper gastrointestinal (GI) tract will be significantly less than those of nonmutant strains. Mice infected with nonmutated Brucella will demonstrate inhibition of phagosome acidification by ammonia.
Mutant and nonmutant strains will demonstrate the ability to transition through intestinal mucosa.
A male patient comes into the clinic complaining of painful urination and a purulent discharge. A sample of the discharge is taken to the lab and after Gram-staining pink spheres in pairs are observed. Which of the following organisms is most likely causing the infection? Escherichia coli Bacillus anthracis Streptococcus pneumoniae Neisseria gonorrhoeae
Neisseria gonorrhoeae
A twenty-year-old patient exhibiting headache, stiff neck, vomiting, and convulsions has Gram-negative diplococcal bacteria in her spinal fluid. The nurse practitioner will likely diagnose infection with Neisseria. Cryptococcus. Haemophilus. Streptococcus.
Neisseria.
Which of the following bacterial genera plays an important role in environmental nitrogen cycles? both Nitrobacter and Rhizobium Rhizobium Nitrobacter, Rhizobium, and Azospirillum Nitrobacter Azospirillum
Nitrobacter, Rhizobium, and Azospirillum
Are Clostridium botulinum vegetative cells required to be present for foodborne botulism to occur? No, foodborne botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves. No, foodborne botulism is caused by the endospore form of Clostridium botulinum, not vegetative cells. Yes, the foodborne botulism is caused by endotoxic shock, which occurs when the cell walls of Clostridium botulinum are disrupted. Yes, the foodborne botulism can only be caused by infection with Clostridium botulinum vegetative cells.
No, foodborne botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves.
What is the term used to describe viral nucleic acid surrounded by a protein "shell"? Capsid Capsomere Icosahedron Nucleocapsid
Nucleocapsid
What portion of bacteriophage T4 enters E. coli? Only the T4 genome enters the bacterial cell. Only the tail fibers penetrate into the interior of the bacterial cell. The entire phage enters into the bacterial cell. No portion of phage T4 actually enters the bacterial cell.
Only the T4 genome enters the bacterial cell.
What type of arrangement occurs when bacilli divide by snapping division? Diplobacilli Streptobacilli Palisades and V-shapes Single bacilli
Palisades and V-shapes
During a lytic replication cycle, what action does a phage take to ensure that its host bacterium does NOT continue synthesizing cellular molecules? Phage enzymes degrade the bacterial DNA. The host DNA is released from the cell. The phage integrates its DNA into the host cell DNA. A phage traps the host DNA in an endosome.
Phage enzymes degrade the bacterial DNA.
Which of the following is a characteristic of biological transmission from Dermacentor to a human host? The human host is infected after drinking water contaminated with Dermacentor eggs. R. rickettsii is transmitted to the human host during a bite, when tick saliva enters the wound. R. rickettsii is transmitted to the human after the human drinks water that has been contaminated by feces from an animal infected with Dermacentor spp. R. rickettsii is transmitted to the human host after the human consumes food that the tick has contacted.
R. rickettsii is transmitted to the human host during a bite, when tick saliva enters the wound.
Which of the following lists the criteria for a diagnosis of Staphylococcus aureus infection? Staphylococcus aureus cultures are coagulase negative, catalase positive, white colonies that are composed of Gram-positive cocci. Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive bacilli. Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive cocci. Staphylococcus aureus cultures are coagulase positive, catalase negative, translucent colonies that are composed of Gram-positive cocci.
Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive cocci.
Which practice would NOT be a good way to prevent foodborne botulism? A. Storing canned foods in the refrigerator. B. Heat canned foods to at least 80 degrees Celsius for 20 minutes before consuming. C. Storing canned foods at room temperature. D. Maintaining an acidic environment below ph 4.5.
Storing canned foods at room temperature.
Which of the following bacteria is the primary cause of necrotizing fasciitis? Staphylococcus aureus Streptococcus pyogenes Bacterioides fragilis Clostridium perfringens
Streptococcus pyogenes
Which genus of high G + C Gram-positive bacteria synthesize antimicrobials such as chloramphenicol, erythromycin, and tetracycline? Streptomyces Corynebacterium Actinomyces Nocardia
Streptomyces
How is the dormant form of Rickettsia rickettsii activated? The bacteria are activated when the tick reaches its adult stage. The warmer temperatures of Spring and Summer activate the bacterium. The bacteria are activated through exposure to acids in the gut of the Dermacentor tick. The bacteria are activated after the tick feeds on a host for several hours.
The bacteria are activated after the tick feeds on a host for several hours.
Why does tuberculosis involve months of antibiotic treatment? The antibiotic treatment is so toxic, it can only be given in very small doses. The bacteria become resistant to the medications after only a month of treatment. The bacteria grow very slowly. The bacteria go into a dormant state.
The bacteria grow very slowly.
Strains of Streptococcus pneumoniae can cause disease only when a capsule is present. Why is the presence of a capsule considered a virulence factor? Streptococcus pneumoniae cannot migrate from the nasopharynx to other areas of the body without a capsule. The capsule prevents the bacterium from being digested after endocytosis in the cells of the host. Streptococcus pneumoniae cannot adhere to the cells of the host without a capsule. The capsule prevents the bacterium from releasing chemicals that announce its presence to the host's immune system.
The capsule prevents the bacterium from being digested after endocytosis in the cells of the host.
What does it mean for a cell to be haploid? The cell has two sets of chromosomes. The cell is incapable of sexual reproduction. The cell has only one set of chromosomes. The cell is a + mating type.
The cell has only one set of chromosomes.
Sexual reproduction often involves two haploid sex cells or gametes. A smaller, mobile, male gamete typically fuses with a larger, nonmobile, female gamete. Why are the sex cells of fungi called + and -, instead of male and female? Scientifically, + translates to male and - translates to female. A + cell has one extra chromosome and a - cell is deficient one chromosome. + cells participate in sexual reproduction, and - cells participate in asexual reproduction. The haploid sex cells of fungi are virtually indistinguishable from one another.
The haploid sex cells of fungi are virtually indistinguishable from one another.
How is the lytic cycle different from the lysogenic cycle with respect to the infected host cell? The viral DNA may integrate into the host genome during the lytic stage. The host cell is allowed to live during the lytic stage. The host cell can only divide during the lytic stage. The host cell dies during the lytic stage.
The host cell dies during the lytic stage.
You have isolated a bacterium that contains a prophage. Which of the following is true concerning the prophage? The phage is in the lytic cycle. The phage is in the lysogenic cycle. The phage particles did not attach properly to their host cells. New phages are being produced.
The phage is in the lysogenic cycle.
What would be the fate of a lytic bacteriophage if the host cell died prior to the assembly stage? The cell could still be revived by the virus. The virus would infect new hosts. The virus would not be able to infect new hosts.
The virus would not be able to infect new hosts.
The polymerization of actin filaments allows Listeria to form pseudopods extending from the host cell. How does this aid the bacteria during infection? They are able to spread to neighboring cells sheltered from detection by the host immune system. The pseudopods form extracellular vesicles similar to endospores. The pseudopods shelter the bacteria from destruction by lysosomes. The pseudopods control the movement of the host cells.
They are able to spread to neighboring cells sheltered from detection by the host immune system.
Which of the following are true for the Chlamydia group of bacteria? They all cause sexually transmitted diseases. They all cause acutely life-threatening disease. They are most reliably detected by fluorescent antibodies. They are all very small in size. They are all intracellular parasites.
They are all very small in size.
Which of the following is CORRECT about the prokaryotes known as deeply branching bacteria? They grow in long branching filaments. They lack peptidoglycan walls. They are commonly found in acidic, anaerobic conditions. They are chemoheterotrophs. They are photosynthetic.
They are commonly found in acidic, anaerobic conditions.
Which of the following is NOT a property of Lactobacilli? They are part of the normal human microbiota. They are members of the high G + C Gram-positive bacteria. They are useful in food production. They are usually non-pathogenic.
They are members of the high G + C Gram-positive bacteria.
When viewed through a microscope, some fungi with branched hyphae look somewhat like plants. Why are fungi not plants? Fungi do not have cell walls, while plants do. They lack nuclei because they are prokaryotes, while plants are eukaryotes. Unlike plants, fungi do not have mitochondria. They lack chloroplasts and therefore cannot perform photosynthesis.
They lack chloroplasts and therefore cannot perform photosynthesis.
Which of the following is NOT a way in which viruses differ from all other living organisms? They cannot self-replicate. They cannot respond to environmental stimuli through metabolic changes. They live inside host cells. They do not grow.
They live inside host cells.
Which of the following is the most common parasitic disease in industrialized nations? giardiasis Trichomonas infection schistosomiasis balantidiasis toxoplasmosis
Trichomonas infection
Bacteria in the genus Cytophaga are capable of digesting a wide range of complex carbohydrates and are important for degrading raw sewage. True False
True
Most viruses CANNOT be seen by light microscopy. True False
True
Several species of Plasmodium cause malaria in humans. True False
True
Various species of Streptomyces are important sources of antibiotics. True False
True
How do clinicians primarily screen for tuberculosis in patients? Throat swab Urinalysis Blood test Tuberculin skin test
Tuberculin skin test
What factor may induce a prophage to enter the lytic cycle? replication of the host bacterium UV light Infection by an additional phage burst time
UV light
Mycobacterium tuberculosis is considered a(n) __________. facultative anaerobe aerobe microaerophile anaerobe
aerobe
What antifungal drug is commonly used to treat systemic mycoses of pathogenic fungi? polymyxin trimethoprim and sulfamethoxazole amphotericin B penicillin
amphotericin B
How do pseudohyphae in yeasts differ from vegetative hyphae in filamentous fungi? Yeasts use pseudohyphae as a means of obtaining nutrients, whereas filamentous fungi use vegetative hyphae as a means of reproduction. Yeasts use pseudohyphae as a means of sexual reproduction, whereas parasitic fungi use their hyphae to invade host tissue. Yeasts use pseudohyphae for obtaining nutrients, whereas filamentous fungi use their vegetative hyphae to invade host tissues. Yeasts use pseudohyphae to invade host tissue, whereas filamentous fungi use their vegetative hyphae for obtaining nutrients.
Yeasts use pseudohyphae to invade host tissue, whereas filamentous fungi use their vegetative hyphae for obtaining nutrients.
A mushroom is an example of _____, which is the reproductive organ of a mold. a mycelium a hypha a fruiting body the male portion of a fungus
a fruiting body
Lysogenic viral DNA which has integrated into the host genome is referred to as a prophage. induction. lytic. lysogeny.
a prophage.
Contact between a phage and its bacterial host occurs by _____. using phage tail fibers using jet-style propulsion using flagella a random collision
a random collision
Which of the following is definitively diagnostic for tuberculosis? Tuberculin skin test Acid-fast stain of sputum Blood-tinged sputum Extensive lung damage
acid fast stain of sputum
Which of the following characteristics would NOT be used to aid in classifying a newly discovered bacterial species? cell wall composition cellular size nutrients required cellular appendages DNA composition
cellular size
Genes for beta-lactamase are present in Burkholderia cepacia but are not normally expressed unless they are induced. Exposure to which of the following agents most likely induced the expression of beta-lactamase resistance in Burkholderia cepacia? ticarcillin/clavulanate cephalexin ceftazidime tobramycin
cephalexin
Once infected with Trypanosoma brucei, the patient's immune system cannot clear the infection and develop immunity because the parasite reproduces by binary fission. changes its glycoprotein surface antigens every time it replicates. matures into infectious trypomastigotes. has flagella that allow it to travel all over the body. invades the central nervous system.
changes its glycoprotein surface antigens every time it replicates.
Some scientists want to study cellullar interactions in colonial organisms; they could use ___________ as a research organism. colonial algae molds Giardia yeasts
colonial algae
Which condition is associated with bacterial infection of the bladder? bacteremia urethritis pyelonephritis cystitis
cystitis
In cystic fibrosis, a defective gene and its protein product lead to the production of thick and dehydrated mucus because of __________. increased transport of chloride and sodium ions outside the cells inflammatory reactions within the bronchioles defective secretion of chloride ions and excess absorption of sodium movement of water into the mucus layer
defective secretion of chloride ions and excess absorption of sodium
The enzyme lysozyme is critical for which of the stages of a bacteriophage T4 infection cycle? entry assembly entry and release synthesis attachment
entry and release
Which of the following is not usually used for treating tuberculosis? Ethambutol Rifampin Erythromycin Isoniazid
erythromycin
Trypanosoma cruzi is introduced into the body by the bite of a tsetse fly, which introduces the trypomastigotes into the body. feces containing trypomastigotes contaminating a bite wound. wearing contact lenses cleaned with contaminated tap water. ingesting food contaminated with the parasite. the bite of a sand fly that has ingested phagocytes containing the parasite.
feces containing trypomastigotes contaminating a bite wound.
Fungi exist as either unicellular yeasts or _____. filamentous molds fruiting bodies uninucleate molds multicellular yeasts
filamentous molds
Some strains of E. coli have __________ allowing them to bind and then enter into epithelial cells of the urethra. flagella gram-negative cell wall fimbriae cilia
fimbriae
Which of the following is NOT a virulence factor associated with Francisella tularensis? endotoxin pili capsule flagella
flagella
Which of the following medications is typically used for superficial candidiasis in AIDS patients? ampicillin amphotericin B fluconazole acyclovir
fluconazole
Diploid cells undergo meiosis producing _____. two haploid nuclei two diploid nuclei a dikaryon four haploid nuclei
four haploid nuclei
What is the recommended medication for treatment of this disease (Yersinia pestis)? erythromycin gentamicin acyclovir griseofulvin
gentamicin
A dikaryon differs from a diploid cell in that the dikaryon _____. is haploid has two separate nuclei has one nucleus with two sets of chromosomes only has chromosomes from the + mating type
has two separate nuclei
If the hyphae of a fungus are septate, this means they _____. are asexual are haploid lack walls separating the cells have crosswalls separating the cells
have crosswalls separating the cells
What is the most common portal of infection for true fungal pathogens that cause systemic mycoses? inhalation sexual transmission ingestion through breaks in the skin
inhalation
A characteristic symptom of necrotizing fasciitis is that the pain __________. is disproportionate to the appearance of the infection occurs only during nighttime hours comes across as a cold sensation is almost insensible
is disproportionate to the appearance of the infection
A primary infection with Mycobacterium tuberculosis typically occurs in the lungs skin sputum spleen
lungs
During the lysogenic cycle, it is possible for integrated phage genes to change the characteristics of the host cell. This is known as _____. synthesis lysogenic conversion induction transduction
lysogenic conversion
Cycles of fever which recur every 48 hours is characteristic of leishmaniasis. malaria. balantidiasis giardiasis. toxoplasmosis.
malaria.
The nutritional requirement to oxidize amino acids and Kreb's cycle intermediates means Rickettsias are __________. obligate intracellular parasites aerobic Gram-negative can only survive in ticks
obligate intracellular parasites
Fungi that cause disease only in people with poor immunity or disrupted microbiomes are called mycotoxicoses. allergic fungi. pathogenic fungi. opportunistic fungi.
opportunistic fungi
Which of the following is a feature shared by viruses and living organisms? presence of cytoplasm the ability to increase in size possession of a genome that directs synthesis of materials necessary for replication metabolic capability responsiveness
possession of a genome that directs synthesis of materials necessary for replication
Which reason is LEAST likely to contribute to the transmission of Adenovirus? aerosolization of the virus presence of a vector viral survival in improperly chlorinated drinking water viral stability outside the body
presence of a vector
Which structure is characteristic of Candida? pseudohyphae cell wall of chitin filamentous hyphae yeast buds
pseudohyphae
Which of the following is an amplifying host of Yersinia pestis? tick flea rat rabbit
rabbit
Which of the following is associated with the attachment of a bacteriophage to a bacterial cell? random collisions chemical attractions receptor specificity both chemical attractions and receptor specificity random collisions, chemical attractions, and receptor specificity
random collisions, chemical attractions, and receptor specificity
Which of the following is a reservoir for the natural endemic cycle of Yersinia pestis? dog tick flea rat
rat
A microbiologist is making agar plates in which to grow bacteria. She can get the agar from red algae. fungi. brown algae. green algae.
red algae.
One of the primary reasons the disease (Mycobacterium tuberculosis) is able to evade the body's immunity is that it __________. resists digestion by phagocytes hides within host epithelial cells is camouflaged in hyaluronic acid produces a capsule
resists digestion by phagocytes
Which of the following enzymes allows retroviruses to transcribe DNA from ssRNA? reverse transcriptase integrase protease DNA polymerase nuclease
reverse transcriptase
In approximately 10% of patients tubercles rupture and reactivate infection. This is known as _____ tuberculosis. tertiary secondary disseminated primary
secondary
Which of the following pathogenic characteristics would best allow Brucella organisms to produce a chronic infection in a host? weakened inflammatory response resistance to complement resistance to antibiotics sequestering of organism within the endoplasmic reticulum
sequestering of organism within the endoplasmic reticulum
Which of the following does not play a role in diagnosing meningitis? Gram stain spinal tap cerebrospinal fluid sputum sample
sputum sample
A bacterial species with spherical cells that have random planes of cell division will form which of the following arrangements? streptococci tetrads sarcinae staphylococci
staphylococci
One of the virulence factors produced by Group A Streptococcus is __________, which can kill neutrophils, the immune system's first responders. Hyaluronidase exotoxin A streptolysin S Streptokinase
streptolysin S
Once entry into the bacterial cell has been achieved, the next step in a lytic replication cycle is _____. release assembly attachment synthesis
synthesis
The definitive host of a parasite is the host for immature stages of the parasite. where the mature form of the parasite occurs. also the vector for the parasite. the host that the parasite name is based on. the host for the dormant stage of the parasite.
where the mature form of the parasite occurs
What part of the United States is endemic for RMSF? the Appalachian region (North Carolina, Kentucky) the Northeast region, particularly along the Atlantic Coast the Rocky Mountain region, including Montana, Wyoming, and Colorado the Gulf Coast region (i.e., states that border the Gulf of Mexico)
the Appalachian region (North Carolina, Kentucky)
In a lytic cycle of replication, release of phages involves _____. keeping the host cell alive exocytosis of phages across the cell wall contact with another uninfected bacterium the bacterial cell bursting open
the bacterial cell bursting open
Which stage of sexual reproduction involves the fusion of hyphae tips from opposite mating types to produce cells with two separate nuclei? the diploid stage the haploid stage Meiosis the dikaryotic stage
the dikaryotic stage
In which population might we observe a higher incidence of thrush? college-age students pregnant women the sexually active the elderly
the elderly
A major difference between the lytic and lysogenic cycles of phage replication is that during the lysogenic phase _____. the bacterial cell is broken open, destroying the cell the host DNA is degraded attachment of the phage involves a random collision the phage genome inserts itself into the host genome
the phage genome inserts itself into the host genome
A patient diagnosed with bacterial meningitis likely was infected through the respiratory route. the digestive system. the skin. sexual activity.
the respiratory route.
Which of the following would NOT be a risk factor associated with the development of histoplasmosis in people? having close contact with bird droppings growing up along the Ohio River valley traveling to China smoking
traveling to China
Protection against Neisseria or Haemophilus meningitis can be provided by antimicrobials. vaccines. serological tests. healthy carriers.
vaccines.
What was the most likely choice for the second antibiotic this patient received? doxycycline cephalosporin penicillin vancomycin
vancomycin
Which type of leishmaniasis is most likely fatal? visceral leishmaniasis mucocutaneous leishmaniasis Gastrointestinal leishmaniasis cutaneous leishmaniasis
visceral leishmaniasis
Which of the following factors would NOT contribute to the development of severe dermatomycoses? corticosteroids for asthma control wearing sandals diabetes mellitus HIV coinfection
wearing sandals
Unicellular, spherical fungi are called protozoa. algae. yeasts. colonial.
yeasts.
How does -lactamase contribute to the virulence of Staphylococcus spp.? β-lactamase triggers blood clot formation. β-lactamase destroys neutrophils. β-lactamase breaks down hyaluronic acid in the matrix between cells. β-lactamase breaks down penicillin and cephalosporin.
β-lactamase breaks down hyaluronic acid in the matrix between cells
