MCB 100 Quiz #10 (Exam 2)

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

B. Change wet diapers often

How do blastoconidia and chlamydoconidia produced by yeast differ from bacterial endospores? A. Blastoconidia and chlamydoconidia are male and female mating structures used for reproduction in yeasts, whereas bacterial endospores are asexual reproductive structures. B. Blastoconidia and chlamydoconidia are produced only by yeasts in extreme conditions, whereas bacterial endospores are asexual reproductive structures. C. Blastoconidida and chlamydoconidia are identical to endospores. D. Blastoconidia and chlamydoconidia are spore structures produced by budding in yeasts, whereas bacterial endospores are produced by bacteria under extreme conditions.

D. Blastoconidia and chlamydoconidia are spore structures produced by budding in yeasts, whereas bacterial endospores are produced by bacteria under extreme conditions

Which of the following statements best describes why the treatment for Tori's fungal infection may result in side effects to her own cells? A. Fungal cells and human host cells both have cell walls made of cellulose. B. Fungal cells and human cells both reproduce via budding. C. Fungal cells and human host cells both have flagella for movement. D. Fungal cells and human cells have a nucleus, multiple organelles, and 80S ribosomes for protein synthesis.

D. Fungal cells and human cells have a nucleus, multiple organelles, and 80S ribosomes for protein synthesis

This disease is also known as Spelunker's Disease and Cave Disease. What is the most likely cause of Nate's illness? A. Trichophyton rubrum B. Rhizopus stolonifer C. Coccidioides immitis D. Histoplasma capsulatum

D. Histoplasma capsulatum

Label the features of a general fungal life cycle with the correct descriptions. Drag the appropriate labels to their respective targets.

*Diagram question*

Label the photograph with the type of fungal spore. Drag the appropriate labels to their respective targets.

*Diagram question*

Tori, a 24-year-old graduate student, had been suffering from a respiratory infection for over a week. She went to the student health center, where the physician prescribed her a broad-spectrum antibiotic. By the end of her round of antibiotics, Tori was no longer suffering from respiratory complications, but she had noticed an increase in itchiness in her genital region. Within a few days, the itchiness was getting worse and was accompanied by a vaginal discharge that had a cheesy consistency and foul odor. Tori returned to the student health center to discuss her condition with the physician. A sample of her discharge was taken and sent to the laboratory for microscopy and plating. Above image shows the microscopy results for the vaginal sample. To confirm the identity of the organism, lab technicians also plated a sample of the organism on a nutrient media and on a Sabouraud dextrose agar plate. Based on the lab results, which organism is most likely causing Tori's new symptoms? A. Candida albicans B. Sporothrix schenckii C. Gardnerella vaginalis D. Trichomonas vaginalis

A. Candida albicans

How are fungal and animal cytoplasmic membranes different from each other? A. Fungal cytoplasmic membranes contain ergosterol, while animal cytoplasmic membranes contain cholesterol. B. Animal cytoplasmic membranes contain cholesterol, while fungal cytoplasmic membranes contain chitin and glucan. C. Animal cytoplasmic membranes contain cholesterol, while fungal cytoplasmic membranes do not contain any sterols. D. Animal cytoplasmic membranes contain ergosterol, while fungal cytoplasmic membranes contain chitin and glucan.

A. Fungal cytoplasmic membranes contain ergosterol, while animal cytoplasmic membranes contain cholesterol

What are dimorphic fungi? A. Fungi that can exist in yeast form and mold form B. Fungi that can form different types of asexual spores C. Fungi that produce asexual spores and sexual spores D. Fungi that produce both aseptate and septate hyphae

A. Fungi that can exist in yeast form and mold form

Identify the fungal genera in the photographs. Drag the appropriate labels to their respective targets. A. Coccidioides immitis B. Candida albicans C. Histoplasma capsulatum

A. Round pink cell surrounded by many pink dots B. Pink rod like cells with bulbs C. Round blue cell with spikes outside

How do humans acquire this disease? A. This disease is most commonly acquired by inhalation. B. This disease is transmitted by the fecal-oral route. C. This is a disease of old age. People under 60 years old are rarely affected. D. This disease is highly contagious and readily passed from person to person by coughing/sneezing.

A. This disease is most commonly acquired by inhalation

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

A. cell-mediated immunity

Which topical medication would likely be recommended for use in this case? A. clotrimazole cream B. polymyxin B ointment C. terbinafine tablets D. griseofulvin tablets

A. clotrimazole cream

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

A. colonial algae

How can this disease best be categorized? A. contagious and chronic B. noncommunicable and chronic C. acute and contagious D. zoonotic and noncommunicable

A. contagious and chronic

The Gram stain revealed nothing that looked like bacteria and Brenda is relieved. On the other hand, since the fungi had reproductive structures, she is worried about the rest of the equipment. Brenda knows that fungal spores spread contamination readily, so she is concerned that even areas that look all right could have spores that would germinate later. Although she is pretty sure that the contaminant is a zygomycete, she knows that she will likely need to grow the fungus on the Sabouraud agar plate and send it in for genetic testing to identify the genus and species. Growing the fungus will take several days and the genetic testing can take a week or more.At lunch, Brenda checks her email. She has been following a story about an outbreak of an atypical respiratory infection in diabetic and immunosuppressed individuals. The latest news is that the infection appears to be fungal and a respiratory patient had died after the infection spread to the brain. Brenda almost chokes on her lunch; she has no reason to believe that the fungal contaminant that she just found is related to this outbreak, but the 2012 meningitis outbreak lingers in her mind. She gets right back to work looking up zygomycosis infections and what kinds of symptoms they can cause. Drag the symptoms and mode of transmission to the correct zygomycoses. A. Rhinocerebral Zygomycota B. Gastrointestinal Zygomycota C. Cutaneous Zygomycota

A. fever, sinus, pain, nasal discharge, inhalation of spores B. abdominal pain, vomiting, ingestion C. contact, skin lesions

The substance appears to be __________. Examine the image seen through the microscope and select the best answer. A. fungi B. common bacteria C. viral D. nonliving E. protozoa

A. fungi *picture question*

What tools would the doctor use to diagnose this disease? A. identification of the budding yeast in KOH-prepared samples of skin scrapings or sputum from the patient B. breathalyzer test for urease production C. test for antibodies to Histoplasma capsulatum D. presence of Gram-negative bacilli in skin scrapings or in the sputum

A. identification of the budding yeast in KOH-prepared samples of skin scrapings or sputum from the patient

Which of the following infections are also caused by C. albicans? Select all that apply. A. oral thrush B. syphilis C. genital warts D. fulminating disease

A. oral thrush D. fulminating disease

Which structure is characteristic of Candida? A. pseudohyphae B. filamentous hyphae C. yeast buds D. cell wall of chitin

A. pseudohyphae

Unicellular, spherical fungi are called A. yeasts. B. protozoa. C. colonial. D. algae.

A. yeasts

What is the most likely cause of this man's current health problems? A. Streptococcus pneumoniae B. Histoplasma capsulatum C. Saccharomyces cerevisiae D. Coccidioides immitis

B. Histoplasma capsulatum

How likely is it that other scouts were infected during the caving camp out? A. The mortality rate for this disease is greater than 75% even when treated. B. It is highly likely that 90% or more of the scouts will show evidence of infection (antibody formation). Only a small percentage of these will get sick. C. Fewer than 5% of the scouts will become infected with Histoplasma capsulatum. D. This is a highly contagious disease and the entire town will be quarantined and the cave will be posted as "off limits."

B. It is highly likely that 90% or more of the scouts will show evidence of infection (antibody formation). Only a small percentage of these will get sick.

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? A. Scientifically, + translates to male and - translates to female. B. The haploid sex cells of fungi are virtually indistinguishable from one another. C. + cells participate in sexual reproduction, and - cells participate in asexual reproduction. D. A + cell has one extra chromosome and a - cell is deficient one chromosome.

B. The haploid sex cells of fungi are virtually indistinguishable from one another

Characterizing the fungal groups.Based on the microscopic image in Part B, the organism appears to belong to the division __________. Select the correct answer. A. Viruses B. Zygomycota C. Basidiomycota D. Ascomycota E. Staphylococcus

B. Zygomycota

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

B. a fruiting body

Which of the following could Tori's physician choose as a treatment for her yeast infection? Select all that apply. A. an antiviral medication, such as acyclovir B. a single oral dose of fluconazole C. an oral narrow-spectrum antibiotic, such as penicillin G D. a topical over-the-counter ointment, such as clotrimazole or miconazole

B. a single oral dose of fluconazole D. a topical over-the-counter ointment, such as clotrimazole or miconazole

If the hyphae of a fungus are septate, this means they _____. A. are haploid B. have crosswalls separating the cells C. are asexual D. lack walls separating the cells

B. have crosswalls separating the cells

What was the source of the infection? A. skin inoculation of spores into the soft tissue while crawling into the cave B. inhalation of spores from the bat guano C. eating food contaminated with bat guano D. bat bites on the head and neck of scouts

B. inhalation of spores from the bat guano

What is the name of the antifungal drug that Nate is taking? A. amphotericin B B. ketoconazole C. griseofulvin D. clotrimazole cream

B. ketoconazole

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

B. the elderly

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

B. vagina

Which of the following factors would NOT contribute to the development of severe dermatomycoses? A. corticosteroids for asthma control B. wearing sandals C. HIV coinfection D. diabetes mellitus

B. wearing sandals

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

C. 40-80%

What is the difference between fungal spores and bacterial endospores? A. Fungal spores are very hardy and more capable of withstanding extreme circumstances than bacterial endospores. B. Fungal spores are survival structures, while bacterial endospores are reproductive structures. C. Fungal spores are reproductive structures, while bacterial endospores are survival structures. D. Fungal spores spread by wind and are therefore smaller than bacterial endospores.

C. Fungal spores are reproductive structures, while bacterial endospores are survival structures

Which of the following is multicellular, chemoheterotrophic, and has a cell wall? A. Cryptosporidium B. Giardia C. Histoplasma D. Plasmodium

C. Histoplasma

Is it critical to determine the fungal agent or agents contributing to this case? Why or why not? A. Yes. Treatment requires penicillin injections weekly for some fungal infections. B. No. Treatment is anecdotal and mostly unsuccessful. C. No. The treatment would be the same. D. Yes. Treatment should be specific for the fungal agent involved.

C. No. The treatment would be the same

Which of the following best explains why Tori developed a new series of symptoms? A. The initial antibiotics were not successful in clearing the respiratory infection, so the organism disseminated to the genitourinary tract. B. Tori contracted a sexually transmitted infection that was not related to the primary respiratory infection. C. The antibiotics that treated Tori's primary respiratory infection also removed some of her normal bacterial flora, resulting in an overgrowth of other organisms. D. Tori's immune system was compromised because of her respiratory infection, and this resulted in a yeast infection.

C. The antibiotics that treated Tori's primary respiratory infection also removed some of her normal bacterial flora, resulting in an overgrowth of other organisms

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

C. The cell has only one set of chromosomes

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

C. has two separate nuclei

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

C. red algae

Athlete's foot is caused by a variety of different fungal infections. The presentation of a severe case would look much like the photograph here. The interdigital spaces and any moist areas of the foot are likely to be affected first. As the disease progresses, the nail and nail bed become affected. Once the nails are infected, the course of treatment must involve three different areas. First, the feet must be kept clean and dry. This includes allowing shoes to air dry for 24 hours between wearings, wearing shoes made of leather or other "breathable" materials, using antifungal powders inside the shoes, changing socks at least twice daily, wearing sandals whenever practical, washing the feet with soap twice daily, and applying an astringent. Additional precautions include always wearing shower shoes in public showers/locker rooms and not sharing towels or wearing another person's shoes to prevent contact with the fungus and reinfection. Second, an appropriate antifungal cream, such as clotrimazole, should be applied to clean, dry feet daily. This helps to kill the infection from the outside toward the inside of the body. Third, in advanced cases that involve the nail bed oral medications are necessary for at least 12 weeks and often up to 6 months (until the new nail is visible and free of fungal discoloration and texture). This kills the fungus from the inside of the skin toward the surface.What would be the most effective oral agent to use for treating the condition depicted in this case? A. ampicillin B. clotrimazole C. terbinafine tablets D. amphotericin B

C. terbinafine tablets

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

C. traveling to China

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

D. They lack chloroplasts and therefore cannot perform photosynthesis

How do pseudohyphae in yeasts differ from vegetative hyphae in filamentous fungi? A. Yeasts use pseudohyphae for obtaining nutrients, whereas filamentous fungi use their vegetative hyphae to invade host tissues. B. Yeasts use pseudohyphae as a means of sexual reproduction, whereas parasitic fungi use their hyphae to invade host tissue. C. Yeasts use pseudohyphae as a means of obtaining nutrients, whereas filamentous fungi use vegetative hyphae as a means of reproduction. D. Yeasts use pseudohyphae to invade host tissue, whereas filamentous fungi use their vegetative hyphae for obtaining nutrients.

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

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

D. amphotericin B

Fungi exist as either unicellular yeasts or _____. A. fruiting bodies B. uninucleate molds C. multicellular yeasts D. filamentous molds

D. filamentous molds

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

D. fluconazole

Diploid cells undergo meiosis producing _____. A. a dikaryon B. two diploid nuclei C. two haploid nuclei D. four haploid nuclei

D. four haploid nuclei

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

D. the dikaryotic stage

The information in the news report seems to match the symptoms and disease progression in rhinocerebral zygomycosis. Brenda tells herself that the incident is unrelated to her findings earlier today because the contaminated machine is for mixing custom ointments and it is highly unlikely that an ointment could transmit rhinocerebral zygomycosis. On one hand she is relieved, but on the other hand she keeps thinking about how many spores are produced by the fungi and how easily they spread. In the back of her mind is the niggling little idea that in her inspections she could easily have missed spores, if there was no actual fungal growth. She heads back to the room to see what other equipment is near the ointment mill and to check the logs for what other drugs are mixed in the area.Which of the following pieces of equipment could be used to make a product that would transmit Zygomycota spores via inhalation? Select the correct answer. A. the skin ointment milling machine B. the mixing machine for powders used in capsules C. The capsule-counting and sealing machine D. the properly functioning autoclave E. a nasal spray bottling machine

E. a nasal spray bottling machine

Brenda's heart sinks. She really hoped she would complete her sampling of the equipment with no biological contaminants present. To check for bacterial contaminants, she prepares a Gram stain slide and swabs a nutrient agar plate. The filamentous-looking growth has Brenda suspecting a fungus, so she prepares a slide with Gomori's methenamine-silver (GMS) stain and swabs a Sabouraud's agar plate. Brenda took a microbiology course in college, and she remembers that the major groups of fungi are distinguishable by their reproductive structures and hyphae. She gets a reference book out and starts to identify the structural features of the fungi she collected. Drag the appropriate label to the figure. Sporangiospores Sporangiophore Sporangium Aseptate hypha

Sporangiospores: lighter orange outer layer of bulb Sporangiophore: stem coming out of bulb Sporangium: bottom of bulb Aseptate hypha: transverse line at the bottom