mcb 100 exam 2

The host DNA is usually degraded during which stage? Attachment Biosynthesis Penetration Assembly Release

Biosynthesis

How do blastoconidia and chlamydoconidia produced by yeast differ from bacterial endospores? Blastoconidia and chlamydoconidia are produced only by yeasts in extreme conditions, whereas bacterial endospores are asexual reproductive structures. Blastoconidida and chlamydoconidia are identical to endospores. 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.

Healthy humans typically become infected with Toxoplasma gondii by ______. A. petting a contaminated cat. B. cleaning a contaminated cat's litter box C. Ingesting undercooked meat containing T. gondii D. working in the garden E. swimming in contaminated lakes

C. Ingesting undercooked meat containing T. gondii

Listeria virulence is directly related to its ability to A. produce powerful toxins that lyse eukaryotic cells. B. form resistant endospores that can withstand harsh chemical environments. C. live within cells and thus avoid exposure to the immune system of its host. D. move rapidly through the body using multiple flagella called comet tails. E. resist most antimicrobial agents due to resistant cell walls.

C. live within cells and thus avoid exposure to the immune system of its host.

Which of the following do not have hyphae associated with them? A. molds B. mushrooms C. yeast D. lichens E. molds and mushrooms

C. yeast

What are the minimal components of a virus? DNA protein DNA or RNA and protein RNA the central dogma- DNA to RNA to protein

DNA or RNA and protein

In which stage is the viral DNA introduced into the cell? Penetration Biosynthesis Release Assembly Attachment

Penetration

Which of the following is multicellular, chemoheterotrophic, and has a cell wall? Plasmodium Cryptosporidium Giardia Histoplasma

Histoplasma

What is the fate of the prophage during the lysogenic stage? It is degraded by the activity of host defense enzymes. It is copied every time the host DNA replicates. It is packaged into viral proteins and maintained until the host is exposed to an environmental stress. It is released from the cell by lysing the cell.

It is copied every time the host DNA replicates.

What is the "gold standard" for treatment of histoplasmosis? amphotericin B griseofulvin 5-fluorocytosine clotrimazole

amphotericin B

Lysogeny is associated with all of the following EXCEPT __________. a prophage increasing virulence of host bacterium bacteriophages animal viruses

animal viruses

MDR-TB is more problematic in a hospital than "regular" tuberculosis because MDR-TB is a dormant infection medical doctor related (meaning that it is acquired from medical staff) antibiotic resistant acid fast

antibiotic resistant

fungi hyphae that lack cross cell walls are called __. myecelial hyphae sexual mycelia asexual buds septate hyphae aseptate hyphae

aseptate hyphae

A phage T4 particle that has lost its tail fibers will have a replication cycle that is blocked at which of the following stages? synthesis assembly entry attachment

attachment

A(n) ________ is a virus that infects bacterial cells. envelope virion bacteriophage nucleocapsid prion

bacteriophage

The outermost layer of a virion fulfills which of the following functions of the virus? protection replication recognition both protection and recognition both recognition and replication

both protection and recognition

Which of the following habits will best prevent infection due to listerosis? Wash your hands after handling pet feces. Avoid eating or drinking pasteurized dairy products. Avoid eating raw fruits and vegetables. Avoid hard cheeses, such as cheddar.

Avoid eating raw fruits and vegetables.

In a plaque assay, a microbiologist counts 20 plaques on a plate. How many plaque-forming units can be assumed to have been present in the original bacterium-virus mixture on the plate if there was no dilution of the mixture prior to plating? 2 10 20 40

20

What percent of people harbor Candida naturally in their body without showing any signs or symptoms? 5-10% less than 1% 100% 40-80%

40-80%

What is the difference between the cell walls of Gram-positive bacteria and those of Gram-negative bacteria? A Gram-positive bacterium has a periplasmic space between an inner and an outer membrane. 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 lipid A embedded in its cell wall. 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.

Lance's physician administered a tuberculin test to determine whether Lance had been infected during his flight from South Africa. How was this test performed? Lance's blood was drawn and examined for the presence of Mycobacterium tuberculosis. An X-ray film of Lance's lungs was taken. A sputum specimen from Lance was cultured for possible growth of Mycobacterium tuberculosis. A small amount of cell wall material from Mycobacterium tuberculosis was injected into Lance's forearm skin

A small amount of cell wall material from Mycobacterium tuberculosis was injected into Lance's forearm skin

Which is the vector of Rickettsia rickettsia? A cockroach A biting fly A flea A tick

A tick

Which of the following statements about archaea is true? A. Archaea lack peptidoglycan in their cell walls. B. The initial amino acid in the peptides of archaea is N-formylmethionine. C. Archaeal cytoplasmic membranes' lipids contain unbranched, linear hydrocarbon chains. D. Archaea are all extremophiles.

A. Archaea lack peptidoglycan in their cell walls.

Why don't archaea appear to cause pathogenesis in humans? A. We haven't found one yet. B. They do cause pathogenesis, we just don't know which diseases yet. C. Antibiotics that kill bacteria also kill archaea. D. Archaea live in extreme environments that humans can't survive.

A. We haven't found one yet.

Toxins are the sole cause of symptoms of A. botulism from Clostridia. B. infections due to Escherichia coli O157:H7. C. wound infections due to Streptococcus pyogenes. D. listeriosis by Listeria monocytogenes. E. diarrhea from Salmonella enterica.

A. botulism from Clostridia.

Which of the following is definitively diagnostic for tuberculosis? Blood-tinged sputum Tuberculin skin test Extensive lung damage Acid-fast stain of sputum

Acid-fast stain of sputum

What is listeriolysin O? A protein that binds to actin filaments. 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.

An enzyme breaks the bacteria free from the phagosome.

In the case of gastrointestinal disease, how can an intoxication be distinguished from an infection? Intoxications may be caused by endotoxin. An intoxication is usually apparent shortly after ingestion, while an infection takes longer. An intoxication usually causes a fever, while an infection does not. Infections are caused by heat-stable agents

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. Because V. cholerae is a gram-negative organism, it is not very effectively treated with antibiotics. As with V. cholerae, the acidic environment of the stomach can have a negative impact on antibiotic activity.

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. Antimicrobial drugs are unable to neutralize anthrax toxin. B. anthracis grows so slowly that it is hard to kill using antimicrobial drugs. Anthrax toxin is absorbed into the bloodstream very quickly.

Antimicrobial drugs are unable to neutralize anthrax toxin.

Which of the following are not eukaryotic microbes? mushrooms archaea water molds protozoa brown algae

Archaea

Which opportunistic fungus is characterized by pseudohyphae? Pneumocystis Histoplasma Aspergillus Candida

Aspergillus

In which stage does formation of mature viruses occur? Release Attachment Biosynthesis Assembly Penetration

Assembly

Botulinum toxin is a _____________________ that binds to the synapses of motor neurons and prevents release of the _____________________ resulting in temporary _____________________ paralysis of associated muscle. A. AB-type neurotoxin, granulosome contents, flaccid B. AB-type neurotoxin, acetylcholine neurotransmitter, flaccid C. AB-type superantigen, lysosomal contents, spastic D. pore-forming neurotoxin, histamine neurotransmitter, spastic E. ADP-ribosylating neurotoxin, anaphylatoxin, spastic

B. AB-type neurotoxin, acetylcholine neurotransmitter, flaccid

Which of the following are not eukaryotic microbes? A. Mushrooms B. Archaea C. Water molds D. Protozoa E. Brown algae

B. Archaea

Why do male teenagers typically have more acne than male adults? A. Sebum production is decreased by testosterone, which is more in adult males. B. The P. acnes bacteria overgrow during puberty when sebum is abundant due to higher testosterone levels, particularly in males. C. During puberty, hair follicles increase in number so more zits can happen, particularly in males. D. The aerobic environment of a hair follicle enhances P. acnes growth. E. All of the above contribute to more acne in male teenagers.

B. The P. acnes bacteria overgrow during puberty when sebum is abundant due to higher testosterone levels, particularly in males.

Which of the following statements is false? A. The grouping of microorganisms in a phylogenetic scheme that is based on nucleic acid sequence data is not always the same as the grouping of microorganisms in a taxonomic scheme based on morpholological traits. B. The cells of prokaryotic organisms are divided into compartments by internal membranes. C. In the most popular current phylogenetic scheme, prokaryotic organisms are divided into two domains called Bacteria and Archaea. D. Most if not all of the chemoautotrophic organisms on Earth are prokaryotes. E. The cells of prokaryotic microorganisms contain 70S ribosomes and most have circular chromosomes.

B. The cells of prokaryotic organisms are divided into compartments by internal membranes.

Which of the following is an advantage for a bacterium having the ability to invade and reside inside host cells: A. The bacteria can bind to antibodies and get transported to lymph nodes. B. The host cytosol is rich in nutrients, if access can be gained by the bacteria. C. The bacteria can colonize and form biofilms. D. Multiple bacteria can use the host cell as a vesicle to exchange metabolites with each other. E. The host cell can shield the bacteria from viruses and parasites.

B. The host cytosol is rich in nutrients, if access can be gained by the bacteria.

What type of organisms do phages infect? Animals Plants Protozoa Bacteria

Bacteria

How does coagulase facilitate bacterial virulence? 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.

Bacteria can hide in the protein clots that result from the action of coagulase.

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? Chagas' disease leishmaniasis trichomoniasis giardiasis

Chagas' disease

Which of the following habits might best prevent infection with Candida? Change wet diapers often. Use condoms during sexual intercourse. Take vitamin C supplements. Irrigation of the vaginal cavity daily with a douching agent.

Change wet diapers often.

How are patients typically infected with listeriosis? Inhalation of dust particles A tick bite Eating undercooked chicken Contaminated food or drink

Contaminated food or drink

Which of the following is not a reason archaea thrive in extreme environments? A. Cytoplasmic enzyme composition B. Cell membrane composition C. Amino acid composition D. Nuclear composition E. DNA composition

D. Nuclear composition

A strain of the Gram-negative bacterium Neisseria gonorrheae, which causes the sexually transmitted disease gonorrhea, has a mutation that has caused the bacterium to lose the ability to produce fimbriae and so it has become less avirulent as a consequence. What function has this pathogen lost? A. The ability to move from one location in the body to another. B. The ability to produce and release endotoxin. C. The ability to grow inside a host cell. D. The ability to adhere to a host cell. E. The ability to cause paralysis.

D. The ability to adhere to a host cell.

All truly pathogenic fungi exist in the environment as molds but grow in the body as spherical yeasts. This trait is known as ______. A. morphogenesis B. mushrooming C. morphotype shift D. dimorphism E. anamorphism

D. dimorphism

Among the virulence factors produced by the Gram-positive bacterium Staphylococcus aureus, the factor that contributes to the ability of S. aureus to invade tissues is A. endotoxin. B. coagulase. C. hemolysin. D. hyaluronidase. E. tracheal cytotoxin.

D. hyaluronidase

A unicellular fungus is a _________, while masses of long, intertwined fungal __________ are called ___________. A. mold / yeast / haustoria B. hypha / mold / slime mold C. yeast / hyphae / slime mold D. yeast / hyphae / mycelia E. mold / mycelia / hyphae

D. yeast / hyphae / mycelia

How might an infected patient transmit listeriosis to another human? Aerosolized droplets in a cough. Fecal-oral route. Through sexual contact. During pregnancy.

During pregnancy.

Why do doctors caution patients who are pregnant to avoid deli meats, cold cuts, and soft cheeses? A. Fermentation of those food by Listeria will cause nausea. B. The Listeria bacteria can make these foods taste sour. C. The Listeria bacteria can degrade the nutrients in the food. D. These foods are soft and easy for the bacteria to spread throughout. E. The Listeria bacteria can easily grow in the uncooked food stored in the refrigerator.

E. The Listeria bacteria can easily grow in the uncooked food stored in the refrigerator.

How do archaeal ribosomes differ the most from bacterial ribosomes? A. Archaeal ribosomes are 80S while bacterial ribosomes are 70S B. Unlike bacteria, archaea don't have ribosomes. C. The DNA in archaeal ribosomes differ from those in bacteria. D. The proteins in archaeal ribosomes differ from those in bacteria. E. The RNA in archaeal ribosomes differ from those in bacteria.

E. The RNA in archaeal ribosomes differ from those in bacteria.

Simple eukaryotes that carry out photosynthesis are known as A. fungi. B. mushrooms. C. euglenids. D. lichens. E. algae.

E. algae.

Fungal hyphae that lack cross walls are called ___________. A. mycelial hyphae B. sexual mycelia C. asexual buds D. septate hyphae E. aseptate hyphae

E. aseptate hyphae

A toxin common to most Gram-negative bacteria is A. neurotoxin. B. coagulase. C. hemolysin. D. collagenase. E. lipid A.

E. lipid A.

Into which type of cell are the Rickettsia introduced in the human host? Kidney cells Skin cells Endothelial cells Liver cells

Endothelial cells

Which of the following is not usually used for treating tuberculosis? Erythromycin Rifampin Isoniazid Ethambutol

Erythromycin

Which of the following events might trigger induction of a temperate bacteriophage? Bacterial conjugation Normal cell division of an infected cell An infected cell entering the logarithmic phase of growth Exposure to UV light

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. Facultative anaerobes require the absence of molecular oxygen. Facultative anaerobes grow equally well in the presence of and in the absence of molecular oxygen. Facultative anaerobes require a small amount of molecular oxygen. Facultative anaerobes can grow without molecular oxygen, but grow faster in its presence.

Facultative anaerobes can grow without molecular oxygen, but grow faster in its presence.

Plasmodium reproduces by binary fission. (T/F)

False

The name Propionibacterium is derived from the fact that the organism produces propionic acid during fermentative metabolism. 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 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 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.

What is the difference between fungal spores and bacterial endospores? Fungal spores spread by wind and are therefore smaller than 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 are reproductive structures, while bacterial endospores are survival structures

What are dimorphic fungi? Fungi that produce both aseptate and septate hyphae Fungi that produce asexual spores and sexual spores Fungi that can form different types of asexual spores 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? 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. Mycoplasmas have a thick layer of mycolic acid.

Gram-positive bacteria have thick cell walls, while mycoplasmas lack cell walls.

The BCG vaccine is available to immunize people against tuberculosis. Had Lance been vaccinated, he would not have been concerned about becoming infected on the airplane. Why was he NOT vaccinated? Immunized patients have a positive skin reaction when tested, even if they have not been infected with Mycobacterium tuberculosis. Such "false positive results" hinder the work of epidemiologists trying to track the spread of the disease. The vaccine provides immune protection only for a low percentage of people. Use of the vaccine in large populations results in the emergence of drug-resistant strains of Mycobacterium tuberculosis. The vaccine requires repeated booster shots because the immune protection is short lived.

Immunized patients have a positive skin reaction when tested, even if they have not been infected with Mycobacterium tuberculosis. Such "false positive results" hinder the work of epidemiologists trying to track the spread of the disease.

Which component of a Gram-negative cell wall can cause fever, vasodilation, inflammation, shock, and blood clotting? The inner membrane Lipid A The periplasm Peptidoglycan

Lipid A

Cycles of fever which recur every 48 hours is characteristic of: malaria. balantidiasis toxoplasmosis. leishmaniasis. giardiasis.

Malaria

If ampicillin is the prescribed treatment for listeriosis, why might a physician instead prescribe trimethoprim-sulfamethoxazole? Listeriosis is often accompanied by a fungal infection. Ampicillin further decreases the ability of the immunocompromised to fight infection. Trimethoprim-sulfamethoxazole is a superior antibiotic. Patients may be allergic to penicillins.

Patients may be allergic to penicillins.

How will the prescribed penicillin kill S. pyogenes that is causing Shelly's infection? Penicillin will disrupt the outer membrane, leading to a loss of structural integrity and death of S. pyogenes. Penicillin will poke holes in the plasma membrane, weakening the cell and leading to cellular lysis. Penicillin will interfere with peptidoglycan synthesis, ultimately weakening the cell wall and leading to cellular lysis. Penicillin will attach to bacterial ribosomes and inhibit protein synthesis, which will lead to the death of S. pyogenes.

Penicillin will interfere with peptidoglycan synthesis, ultimately weakening the cell wall and leading to cellular lysis.

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 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 during a bite, when tick saliva enters the wound. 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.

How is the dormant form of Rickettsia rickettsii activated? The warmer temperatures of Spring and Summer activate the bacterium. The bacteria are activated when the tick reaches its adult stage. The bacteria are activated after the tick feeds on a host for several hours. 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.

What does it mean for a cell to be haploid? The cell has only one set of chromosomes. The cell has two sets of chromosomes. The cell is a + mating type. The cell is incapable of sexual reproduction.

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? + cells participate in sexual reproduction, and - cells participate in asexual reproduction. A + cell has one extra chromosome and a - cell is deficient one chromosome. Scientifically, + translates to male and - translates to female. 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 can only divide during the lytic stage. The host cell dies during the lytic stage. The host cell is allowed to live 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 particles did not attach properly to their host cells. The phage is in the lysogenic cycle. New phages are being produced.

The phage is in the lysogenic cycle.

An appropriately stained smear was prepared of a sputum specimen obtained from the sick woman on Lance's flight. Using oil-immersion magnification on your microscope, what would you observe that would aid in the diagnosis of tuberculosis? acid-fast rods Gram-positive cocci Gram-positive rods acid-fast cocci

acid-fast rods

What would be the fate of a lytic bacteriophage if the host cell died prior to the assembly stage? The virus would not be able to infect new hosts. 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 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 shelter the bacteria from destruction by lysosomes. The pseudopods control the movement of the host cells. The pseudopods form extracellular vesicles similar to endospores.

They are able to spread to neighboring cells sheltered from detection by the host immune system.

When viewed through a microscope, some fungi with branched hyphae look somewhat like plants. Why are fungi not plants? They lack nuclei because they are prokaryotes, while plants are eukaryotes. They lack chloroplasts and therefore cannot perform photosynthesis Unlike plants, fungi do not have mitochondria. Fungi do not have cell walls, while plants do.

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 respond to environmental stimuli through metabolic changes. They do not grow. They cannot self-replicate. They live inside host cells.

They live inside host cells.

Some studies have indicated that the ID50 for Vibrio cholerae can be as high as 108 organisms. Which of the following most likely explains the requirement for this relatively high ID50? Because V. cholerae cells are relatively small compared to host cells, thousands of bacteria must infect each cell to cause disease. Because the major virulence factor of V. cholerae is cholera toxin, large numbers of bacteria are required to produce enough toxin to cause disease. To establish infection, V. cholerae must survive the host immune response and the acidic environment of the stomach. V. cholerae does not produce enough virulence factors to overcome the host response and cause disease.

To establish infection, V. cholerae must survive the host immune response and the acidic environment of the stomach.

Which of the following is the most common parasitic disease in industrialized nations? Trichomonas infection schistosomiasis balantidiasis toxoplasmosis giardiasis

Trichomonas infection

Most viruses cannot be seen by light microscopy. (T/F)

True

Several species of Plasmodium cause malaria in humans. (T/F)

True

How is tuberculosis transmitted? aerosol droplets released by a cough or sneeze drinking pasteurized milk fecal/oral route sharing "dirty" needles between IV drug users

aerosol droplets released by a cough or sneeze

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 to invade host tissue, whereas filamentous fungi use their vegetative hyphae for obtaining nutrients. 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.

A mushroom is an example of _____, which is the reproductive organ of a mold. a hypha a mycelium the male portion of a fungus a fruiting body

a fruiting body

Lysogenic viral DNA which has integrated into the host genome is referred to as lysogeny. a prophage. induction. lytic.

a prophage.

What antifungal drug is commonly used to treat systemic mycoses of pathogenic fungi? penicillin amphotericin B polymyxin trimethoprim and sulfamethoxazole

amphotericin B

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? cell-mediated immunity The organism is cleared from their body in urine. Specific antibodies are produced in response to antigens on the pathogen and the fungus is neutralized. The organism is cleared from their body by coughing.

cell-mediated immunity

To diagnose meningitis due to Listeria infection, physicians will first examine a patient's ___. blood fecal samples cerebrospinal fluid gall bladder

cerebrospinal fluid

Once infected with Trypanosoma brucei, the patient's immune system: cannot clear the infection and develop immunity because the parasite: because the parasite has flagella that allow it to travel all over the body. changes its glycoprotein surface antigens every time it replicates. matures into infectious trypomastigotes. reproduces by binary fission. invades the central nervous system.

changes its glycoprotein surface antigens every time it replicates

What type of nucleic acid is not found in the genome of viruses? single stranded DNA circular single stranded DNA linear double stranded DNA circular double stranded DNA Linear single stranded DNA

circular single stranded DNA

Some scientists want to study cellullar interactions in colonial organisms; they could use ___________ as a research organism. yeasts Giardia molds colonial algae

colonial algae

All truly pathogenic fungi exist in the environment as molds but grow in the body as spherical yeasts. this trait is known as __. morphogenesis mushrooming mophotype shift dimorphism anamorphism

dimorphism

The enzyme lysozyme is critical for which of the stages of a bacteriophage T4 infection cycle? entry and release attachment assembly synthesis entry

entry and release

Contact with infected cats and their feces is the only mode of transmission of Toxoplasma to humans. (T/F)

false

Trypanosoma cruzi is introduced into the body by: ingesting food contaminated with the parasite. wearing contact lenses cleaned with contaminated tap water. the bite of a tsetse fly, which introduces the trypomastigotes into the body. feces containing trypomastigotes contaminating a bite wound. 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 _____. uninucleate molds filamentous molds fruiting bodies multicellular yeasts

filamentous molds

Which of the following medications is typically used for superficial candidiasis in AIDS patients? fluconazole amphotericin B acyclovir ampicillin

fluconazole

Diploid cells undergo meiosis producing _____. two haploid nuclei two diploid nuclei a dikaryon four haploid nuclei

four haploid nuclei

A dikaryon differs from a diploid cell in that the dikaryon _____. only has chromosomes from the + mating type has one nucleus with two sets of chromosomes has two separate nuclei is haploid

has two separate nuclei

If the hyphae of a fungus are septate, this means they _____. lack walls separating the cells are haploid are asexual 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? sexual transmission inhalation ingestion through breaks in the skin

inhalation

which of the following statements about candida is false? it is present in the digestive tract of 40-80% of all healthy individuals. it can be transmitted during sexual contact it causes thrush in children it can be passed on to babies during childbirth it can be easily treated with topical antifungals in immunocompromised individuals

it can be easily treated with topical antifungals in immunocompromised individuals

A primary infection with Mycobacterium tuberculosis typically occurs in the lungs spleen skin sputum

lungs

Which of the following symptoms is LEAST characteristic of Clostridium perfringens food poisoning? moderate vomiting and fever short incubation period sudden onset of diarrhea severe abdominal cramping

moderate vomiting and fever

The nutritional requirement to oxidize amino acids and Kreb's cycle intermediates means Rickettsias are __________. can only survive in ticks obligate intracellular parasites aerobic Gram-negative

obligate intracellular parasites

Fungi that cause disease only in people with poor immunity or disrupted microbiomes are called mycotoxicoses opportunistic fungi. pathogenic fungi. allergic fungi.

opportunistic fungi.

Which of the following is a feature shared by viruses and living organisms? presence of cytoplasm metabolic capability the ability to increase in size responsiveness possession of a genome that directs synthesis of materials necessary for replication

possession of a genome that directs synthesis of materials necessary for replication

Which structure is characteristic of Candida? yeast buds filamentous hyphae cell wall of chitin pseudohyphae

pseudohyphae

Analysis of the second swab has confirmed that the causative organism is Streptococcus pyogenes, a gram-positive organism. Imagine that you are the technician looking at the Gram stain from Shelly's culture. What would you expect to see as you look through the microscope? pink, rod-shaped organisms arranged in pairs pink, spherical-shaped organisms arranged in chainlike formations purple, spherical-shaped organisms arranged in chainlike formations purple, spherical-shaped organisms arranged in grapelike clusters

purple, spherical-shaped organisms arranged in chainlike formations

Which of the following is associated with the attachment of a bacteriophage to a bacterial cell? chemical attractions receptor specificity random collisions both chemical attractions and receptor specificity random collisions, chemical attractions, and receptor specificity

random collisions, chemical attractions, and receptor specificity

A microbiologist is making agar plates in which to grow bacteria. She can get the agar from fungi. brown algae. green algae. red algae.

red algae.

The definitive host of a parasite is: the host that the parasite name is based on. also the vector for the parasite. the host for immature stages of the parasite. the host for the dormant stage of the parasite. where the mature form of the parasite occurs.

where the mature form of the parasite occurs.

the period of time required to complete the lytic cycle is called__. the lytogenic time the burst time lytic accumulation lysogeny

the burst time

Which stage of sexual reproduction involves the fusion of hyphae tips from opposite mating types to produce cells with two separate nuclei? the haploid stage the dikaryotic stage the diploid stage Meiosis

the dikaryotic stage

In which population might we observe a higher incidence of thrush? college-age students the sexually active pregnant women the elderly

the elderly

Which of the following would NOT be a risk factor associated with the development of histoplasmosis in people? smoking growing up along the Ohio River valley having close contact with bird droppings traveling to China

traveling to China

In which part of the body would candidiasis present as curd-like? vagina folds of skin toe nails in the mouth

vagina

Which type of leishmaniasis is most likely fatal? cutaneous leishmaniasis Gastrointestinal leishmaniasis mucocutaneous leishmaniasis visceral leishmaniasis

visceral leishmaniasis

Which of the following do not have hyphae associated with them? molds mushrooms yeast lichens molds and mushrooms

yeast

A unicellular fungus is a __, while masses of long, intertwined fungal __ are called__ Mold, yeast, haustoria hypha, mold, slime mold yeast, hypae, slime mold yeast, hypae, myecelia mold, myecelia, hypae

yeast, hypae, myecelia

Unicellular, spherical fungi are called algae. protozoa. colonial. yeasts.

yeasts.

What is the word used to refer to diseases transmissible from animals to humans? endemic disease epidemic disease notifiable disease zoonoses

zoonoses