Micro 57 Flashcards

What role do fungi play?

A. Fix atmospheric nitrogen
B. Produce molecular oxygen
C. Degrade organic matter
D. Synthesize inorganic minerals

A fungus grows on a fallen, decomposing tree without obtaining nutrients from a living host. What is it classified as?

A. Saprobe
B. Parasite
C. Symbiont
D. Autotroph

Which substances are major structural components of the fungal cell wall?

A. Cellulose and cholesterol
B. Peptidoglycan and glucan
C. Chitin and ergosterol
D. Chitin and glucan

Which sterol distinguishes fungal cell membranes from most human cell membranes?

A. Cholesterol
B. Ergosterol
C. Lanosterol
D. Cardiolipin

Modern fungal species classification primarily depends on which criterion?

A. Ability to mate successfully
B. Concordant multiple-gene genealogies
C. Similar microscopic appearance
D. Identical environmental habitat

Under the gene-genealogy species concept, which feature is insufficient by itself to define a species?

A. Multiple concordant DNA sequences
B. Agreement across separate gene loci
C. Shared morphology or mating ability
D. Consistent multilocus genetic clustering

Elongated daughter cells that remain attached to yeast cells form which structure?

A. Pseudohyphae
B. Arthroconidia
C. Sporangia
D. Asci

A mold grows as long, branching filamentous structures. What are these structures called?

A. Pseudohyphae
B. Conidia
C. Mycelia
D. Hyphae

A fungal hypha increases in length primarily through which process?

A. Basal budding
B. Septal fragmentation
C. Apical extension
D. Binary fission

A laboratory isolate produces threadlike tubular structures that elongate by apical extension. This organism is best classified as a:

A. Yeast
B. Protozoan
C. Mold
D. Bacterium

A visible fungal colony contains an interconnected mass of many hyphae. What is this mass called?

A. Ascocarp
B. Mycelium
C. Sporangium
D. Pseudohypha

What occurs during the thallic process of conidial reproduction?

A. Spores fuse within asci
B. Yeasts undergo binary fission
C. Sporangia release internal spores
D. Hyphal segments fragment

Individual cells produced by fragmentation of hyphal segments are called what?

A. Arthroconidia
B. Ascospores
C. Sporangiospores
D. Blastoconidia

A fungus grows as mold under one condition and yeast under another. Which term describes this ability?

A. Dimorphic
B. Saprobic
C. Septate
D. Pleomorphic

Which group contains only primary fungal metabolites?

A. Antibiotics, ethanol, aflatoxins
B. Ergot alkaloids, glycerol, ethanol
C. Citric acid, ethanol, glycerol
D. Aflatoxins, antibiotics, citric acid

Which group contains only secondary fungal metabolites?

A. Citric acid, ethanol, glycerol
B. Antibiotics, ergot alkaloids, aflatoxins
C. Glucose, ethanol, citric acid
D. Glycerol, aflatoxins, pyruvate

What are the two major types of asexual fungal spores?

A. Ascospores and basidiospores
B. Zygospores and ascospores
C. Arthrospores and basidiospores
D. Sporangiospores and conidia

Members of the order Mucorales characteristically produce which asexual spores?

A. Ascospores
B. Basidiospores
C. Conidia
D. Sporangiospores

Which genera are representative members of Mucorales?

A. Rhizopus and Mucor
B. Aspergillus and Penicillium
C. Cryptococcus and Malassezia
D. Fusarium and Trichosporon

Which organisms characteristically reproduce asexually through conidia?

A. Rhizopus, Mucor, Cryptococcus
B. Malassezia, Mucor, Pneumocystis
C. Aspergillus, Penicillium, dermatophytes
D. Rhizopus, Trichosporon, Mucor

Approximately what proportion of all named fungal species belongs to Ascomycota?

A. Ten percent
B. Nearly fifty percent
C. Seventy-five percent
D. Almost all species

Sexual reproduction in members of Ascomycota produces which spores?

A. Arthroconidia
B. Sporangiospores
C. Ascospores
D. Blastoconidia

Ascospores are produced within which specialized saclike structure?

A. Basidium
B. Sporangium
C. Conidiophore
D. Ascus

Which list contains the four stated classes of Ascomycota?

A. Pneumocystidomycetes, Saccharomycetes, Eurotiomycetes, Sordariomycetes
B. Mucoromycetes, Basidiomycetes, Eurotiomycetes, Zygomycetes
C. Saccharomycetes, Tremellomycetes, Mucorales, Onygenales
D. Pneumocystidomycetes, Agaricomycetes, Ustilaginomycetes, Microsporidia

Which Ascomycota class was described to include Pneumocystis carinii?

A. Saccharomycetes
B. Pneumocystidomycetes
C. Eurotiomycetes
D. Sordariomycetes

Before being classified as a fungus, Pneumocystis carinii was considered what?

A. Bacterium
B. Protozoan
C. Helminth
D. Virus

According to the provided material, how does Pneumocystis jirovecii reproduce asexually?

A. Budding
B. Apical extension
C. Hyphal fragmentation
D. Binary fission

How many spores are present when the mature Pneumocystis structure is fully developed?

A. Two spores
B. Four spores
C. Eight spores
D. Sixteen spores

The medically important dermatophytes belong to which fungal order?

A. Onygenales
B. Hypocreales
C. Mucorales
D. Saccharomycetales

Within Sordariomycetes, which order contains teleomorphs related to Fusarium?

A. Onygenales
B. Eurotiales
C. Mucorales
D. Hypocreales

Hypocreales contains the teleomorphic forms of which anamorphic genus?

A. Aspergillus
B. Fusarium
C. Cryptococcus
D. Malassezia

Which genera are included in the phylum Basidiomycota?

A. Cryptococcus, Malassezia, Trichosporon
B. Aspergillus, Penicillium, Fusarium
C. Rhizopus, Mucor, Absidia
D. Pneumocystis, Histoplasma, Blastomyces

In culture, organisms of Basidiomycota often have which colony appearance?

A. Slow-growing pigmented colonies
B. Mucoid green colonies
C. Fast-growing sterile white colonies
D. Black sporulating colonies

Which microscopic structure may help identify Basidiomycota in culture?

A. Arthroconidia
B. Sporangia
C. Clamp connections
D. Germ tubes

Which description best defines a clamp connection?

A. Hyphal outgrowth bypassing a septum
B. Spore contained within an ascus
C. Bud elongating into pseudohyphae
D. Fragment released from a hypha

What is the principal function of a fungal clamp connection?

A. Produce asexual conidia
B. Facilitate nuclear migration
C. Digest extracellular organic matter
D. Promote apical hyphal growth

Most filamentous basidiomycetes occupy which ecological role?

A. Aquatic photosynthetic organisms
B. Wood-rotting fungi
C. Intracellular animal parasites
D. Nitrogen-fixing soil organisms

Which filamentous basidiomycete most frequently causes human infection?

A. Mucor circinelloides
B. Aspergillus fumigatus
C. Schizophyllum commune
D. Pneumocystis jirovecii

Mucorales produce asexual spores inside which structure?

A. Ascus
B. Basidium
C. Sporangium
D. Conidiophore

The stalk supporting a Mucorales sporangium is called what?

A. Sporangiophore
B. Conidiophore
C. Rhizoid
D. Columella

A sporangiophore terminates in which bulbous swelling?

A. Rhizoid
B. Ascocarp
C. Arthroconidium
D. Columella

Which rootlike structures may appear in Mucorales?

A. Pseudohyphae
B. Blastoconidia
C. Clamp connections
D. Rhizoids

Rhizoids are especially helpful for performing what task?

A. Distinguishing Mucorales genera
B. Identifying fungal metabolites
C. Measuring fungal growth rates
D. Detecting sexual reproduction

Serious fungal infections are especially problematic in which patients?

A. Immunocompetent adolescents
B. Vaccinated young adults
C. Patients with hypertension
D. Immunocompromised patients

Which term is synonymous with tinea unguium?

A. Onychomycosis
B. Tinea corporis
C. Tinea capitis
D. Pityriasis versicolor

Endemic systemic mycoses initially establish infection where?

A. Lung
B. Skin
C. Intestine
D. Genital tract

After primary pulmonary infection, systemic mycoses may undergo what?

A. Local keratin invasion
B. Dissemination to other organs
C. Permanent pulmonary confinement
D. Immediate spore destruction

Serious fungal infections are especially problematic in which patients?

A. Immunocompetent adolescents
B. Vaccinated young adults
C. Patients with hypertension
D. Immunocompromised patients

Fungi belong to which cellular classification?

A. Prokaryotes
B. Archaea
C. Eukaryotes
D. Acellular organisms

Which form represents the simplest fungal growth type?

A. Mold
B. Yeast
C. Mycelium
D. Sporangiophore

According to the provided material, yeast replicates through which processes?

A. Apical extension and fragmentation
B. Meiosis and ascospore release
C. Nuclear fission and blastoconidia formation
D. Sporangium formation and germination

Elongated yeast daughter cells may form which structure?

A. True hyphae
B. Sporangia
C. Clamp connections
D. Pseudohyphae

Which description best characterizes pseudohyphae?

A. Bulbous terminal swellings
B. Sausage-like elongated daughter cells
C. Rootlike anchoring structures
D. Thin-walled sexual sacs

Filamentous growth by molds produces which structures?

A. Pseudohyphae
B. Hyphae
C. Blastoconidia
D. Asci

Which description best characterizes fungal hyphae?

A. Threadlike tubular structures
B. Round intracellular spores
C. Rootlike septal outgrowths
D. Saclike reproductive structures

Fungi reproduce primarily through formation of what?

A. Spores
B. Cysts
C. Trophozoites
D. Endospores

Fungal spores may occur in which forms?

A. Sexual or asexual
B. Motile or flagellated
C. Diploid or bacterial
D. Enveloped or nonenveloped

The fungal form producing sexual spores is called what?

A. Anamorph
B. Teleomorph
C. Mycelium
D. Sporangiophore

The fungal form producing asexual spores is called what?

A. Teleomorph
B. Basidiomorph
C. Anamorph
D. Ascocarp

Which are the two major asexual spore types?

A. Ascospores and basidiospores
B. Zygospores and arthrospores
C. Sporangiospores and conidia
D. Basidiospores and blastospores

Which structure serves as the principal airborne asexual reproductive element for dissemination of many medically important fungi?

A. Ascospore
B. Basidiospore
C. Conidium
D. Zygospore

How many stated classes comprise Ascomycota?

A. Two
B. Three
C. Five
D. Four

Which list contains the four Ascomycota classes?

A. Mucorales, Onygenales, Eurotiales, Hypocreales
B. Tremellomycetes, Mucoromycetes, Agaricomycetes, Microsporidia
C. Pneumocystidomycetes, Saccharomycetes, Eurotiomycetes, Sordariomycetes
D. Basidiomycetes, Zygomycetes, Chytridiomycetes, Glomeromycetes

Which Ascomycota class contains Pneumocystis organisms?

A. Saccharomycetes
B. Eurotiomycetes
C. Sordariomycetes
D. Pneumocystidomycetes

Pneumocystis exists vegetatively in which form?

A. Trophic form
B. Hyphal form
C. Sporangial form
D. Conidial form

How does the Pneumocystis trophic form reproduce asexually?

A. Budding
B. Binary fission
C. Apical extension
D. Hyphal fragmentation

Which Ascomycota class contains vegetative yeast cells?

A. Eurotiomycetes
B. Saccharomycetes
C. Pneumocystidomycetes
D. Sordariomycetes

Compared with bacteria, fungi generally:

A. Grow more rapidly with doubling times measured in minutes.
B. Lack nuclei.
C. Have doubling times measured in hours.
D. Divide exclusively by binary fission.
E. Have peptidoglycan cell walls.

Saccharomycetes vegetative cells proliferate through which processes?

A. Ascospore release or budding
B. Apical extension or budding
C. Hyphal fragmentation or fission
D. Budding or fission

Which class forms a thin-walled ascus containing haploid ascospores?

A. Pneumocystidomycetes
B. Saccharomycetes
C. Eurotiomycetes
D. Sordariomycetes

Which Ascomycota class is described as reproducing sexually?

A. Eurotiomycetes
B. Saccharomycetes
C. Pneumocystidomycetes
D. Sordariomycetes

Members of Basidiomycota undergo which type of reproduction?

A. Sexual reproduction
B. Binary fission
C. Asexual budding
D. Hyphal fragmentation

A fungal infection remains confined to the outermost skin and hair surfaces. How is it classified?

A. Cutaneous mycosis
B. Endemic mycosis
C. Subcutaneous mycosis
D. Superficial mycosis

Superficial mycoses are limited primarily to which structures?

A. Skin surface and hair
B. Dermis and subcutaneous tissue
C. Lungs and bloodstream
D. Muscle and connective tissue

The order Eurotiales contains the teleomorphs of which anamorphic genera?

A. Candida and Saccharomyces
B. Fusarium and Scedosporium
C. Aspergillus and Penicillium
D. Histoplasma and Blastomyces
E. Trichophyton and Microsporum

A patient has hypopigmented, finely scaling patches on the trunk. Which diagnosis is most likely?

A. Tinea nigra
B. Tinea unguium
C. Pityriasis versicolor
D. Sporotrichosis

Which findings characterize pityriasis versicolor?

A. Painful ulcerated nodules
B. Discoloration and skin scaling
C. Black patches on palms
D. Inflamed dystrophic nails

A patient develops an asymptomatic dark macule on the palm. Which superficial mycosis is most likely?

A. Tinea nigra
B. Pityriasis versicolor
C. Tinea unguium
D. Cutaneous candidiasis

Which description best characterizes tinea nigra?

A. Scaly depigmented trunk patches
B. Inflamed interdigital fissures
C. Brown-black palmar macules
D. Deep ulcerating skin nodules

Cutaneous mycoses primarily infect which tissues?

A. Dermis and blood vessels
B. Lungs and lymphatics
C. Muscle and connective tissue
D. Keratinized skin, hair, nails

Unlike superficial mycoses, cutaneous mycoses commonly produce what?

A. Host response and symptoms
B. Immediate systemic dissemination
C. No inflammatory response
D. Infection limited to lungs

Fungal infections caused by dermatophytes are called what?

A. Candidiases
B. Dermatophytoses
C. Endemic mycoses
D. Chromoblastomycoses

Which structures can be involved in dermatophytosis?

A. Brain, meninges, spinal cord
B. Liver, spleen, kidneys
C. Skin, hair, and nails
D. Muscle, arteries, cartilage

Tinea unguium refers to dermatophyte infection of what?

A. Scalp hair
B. Toenail or fingernail
C. Palmar epidermis
D. Interdigital skin

Subcutaneous mycoses typically involve which tissue level?

A. Superficial stratum corneum
B. Hair shafts
C. Deeper skin and connective tissue
D. Alveolar spaces

Which tissues may be affected by subcutaneous fungal infection?

A. Muscle and connective tissue
B. Hair shaft and nail plate
C. Bronchi and alveoli
D. Intestinal mucosa and colon

Subcutaneous fungal infections commonly enter through which mechanism?

A. Respiratory droplet inhalation
B. Traumatic tissue implantation
C. Mosquito vector transmission
D. Fecal-oral ingestion

Tissue injury during subcutaneous mycoses may result primarily from what?

A. Absent host recognition
B. Viral toxin production
C. Excessive antibody deficiency
D. Damaging immune response

Endemic mycoses are caused by which fungal category?

A. Classic dimorphic pathogens
B. Superficial dermatophytes
C. Nonpathogenic skin yeasts
D. Filamentous basidiomycetes only

Why are endemic mycoses also called systemic mycoses?

A. They remain on hair shafts
B. They infect nails exclusively
C. They can disseminate internally
D. They produce only palmar lesions

Which statement best describes endemic fungal pathogens?

A. They infect only immunosuppressed patients
B. They can infect healthy individuals
C. They remain superficial in everyone
D. They require damaged nails

Endemic fungi differ from many opportunistic fungi because they are what?

A. True primary pathogens
B. Restricted skin commensals
C. Noninvasive environmental yeasts
D. Exclusively hospital-acquired organisms

A healthy adult inhales a dimorphic fungus and develops pulmonary infection with later dissemination. How is this infection classified?

A. Superficial mycosis
B. Cutaneous mycosis
C. Subcutaneous mycosis
D. Endemic systemic mycosis

Which comparison correctly distinguishes superficial from cutaneous mycoses?

A. Both invade connective tissue
B. Superficial asymptomatic; cutaneous inflammatory
C. Superficial systemic; cutaneous localized
D. Both infect healthy lungs

These are things _____ _____ can cause:

1. Oral and esophageal thrush
2. Vulvovaginitis
3. Diaper rash
4. Infective endocarditis
5. Disseminated candidiasis
6. Chronic mucocutaneous candidiasis

These 2 fungi cause _______:

1. Aspergillus
2. Cryptococcus neoformans

Which fungi can cause dacryocystitis and canaliculitis?

A. Fusarium

B. Cryptococcus neoformans

C. Histoplasma capsulatum

D. Candida albicans

Which fungi can cause dacryocystitis and canaliculitis?

A. Rhizopus

B. Aspergillus niger

C. Histoplasma capsulatum

D. Malassezia furfur