Mycology

Question 1

are fungi pro or eukaryotic

Answer 1

eukaryotic

Question 2

uni vs multicellular fungi

Answer 2

uni: yeast
multi: mold and mushrooms

Question 3

how do fungi get nutrition

Answer 3

non-photosynthetic heterotrophs

requires organic substrates to get its carbon for growth
- performs extracellular digestion then absorbs nutrients

Question 4

saprophytic

Answer 4

exists in the environment; lives in dead or decaying organic matter (ex. soil)

Question 5

parasitic

Answer 5

exists within a host

Question 6

are fungi motile

Answer 6

no

Question 7

what kind of environment do fungi thrive in

Answer 7

wet/humid
room temperature
acidic pH

Question 8

are fungi aerobic or anaerobic

Answer 8

aerobic

except yeast - facultative anaerobe

Question 9

what are predisposing factors for fungal infection

Answer 9

• prolonged antibiotic therapy
• immunosuppression
• immaturity/malnutrition
• endocrine disorders

Question 10

yeast

Answer 10

unicellular, oval or spherical cells that are larger than most bacteria

Question 11

molds

Answer 11

multicellular mycelium

Question 12

hyphae

Answer 12

tubular structure of the growing mycelium

Question 13

septate vs non-septate

Answer 13

hyphae separated by cross-walls vs continuous hyphae with no separations

Question 14

dematiaceous fungi

Answer 14

dark pigmented molds

Question 15

hyaline fungi

Answer 15

non-pigmented molds

Question 16

conidiophores

Answer 16

hyphae that produce conidia for asexual reproduction

Question 17

sporangiophores

Answer 17

hyphae that produce spores for asexual reproduction

Question 18

conidia/spores

Answer 18

infective stage of mold
- environmentally resistant

released when sporangium ruptures
- allows for aerial dissemination

Question 19

dimorphic fungi

Answer 19

fungi that change from mold to yeast depending on environment

ex. thermal
- mold at room temp
- yeast at warm temp

Question 20

sexual vs asexual fungal reproduction

Answer 20

sexual: rare; fusion of haploid nuclei then meiosis

asexual: most common; division by mitosis

Question 21

mechanisms of asexual reproduction in fungi

Answer 21

1. sporulation
2. hyphae fragmentation
3. budding (yeast only)

Question 22

classification of fungal disease

Answer 22

• superficial (dermatophytosis, dermatomycoses)
• subcutaneous
• systemic

Question 23

capsule

Answer 23

compact capsule or external coating composed of polysaccharides that aid in adherence or clumping

protects fungi in the host or in the environment
- can be antigenic and anti-phagocytic

Question 24

fungal cell wall

Answer 24

lies outside cytoplasmic membrane

composed of polysaccharide chains cross-linked with proteins and glycoproteins
- contains chitin
- different fungal species have common polysaccharides in cell wall

Question 25

fungi cytoplasmic membrane

Answer 25

bilayer membrane that contains sterols (ergosterol, zymosterol) NOT cholesterol like in mammals

Question 26

what is the most common immune response to fungi

Answer 26

cell mediated formation of granulomatous lesions - type IV hypersensitivity antibodies not effective

Question 27

what must the media used for propagating fungi contain

Answer 27

carbon source

Question 28

cutaneous mycoses

Answer 28

- dermatomycoses - dermatophytoses

Question 29

dermatomycoses

Answer 29

opportunistic infections of skin or mucocutaneous junctions from overgrowth of fungi ex. malassezia pachydermatis and candida albicans

Question 30

malassezia pachydermatis

Answer 30

yeast causes otitis externa and dermatitis in dogs

Question 31

candida albicans

Answer 31

yeast - endogenous; can overgrow esp. in immunocompromised hosts inhabits mucous membranes of animals and birds causes yellow/gray plaques and ulceration

Question 32

dermatophytoses

Answer 32

subset of dermatomycoses caused only by dermatophytes invasion and destruction of keratinized structures - superficial skin, hair, feathers, hooves, claws, etc ex. ringworm

Question 33

how to diagnose dermatophytosis

Answer 33

hair plucks skin scrapings on edge of lesion

Question 34

chytridiomycosis

Answer 34

infectious disease of amphibians casued by batrachochytrium dendrobatidis affects skin --> decreased ability to breathe, hydrate, osmoregulate

Question 35

white nose syndrome

Answer 35

infectious disease of bats caused by pseudogymnokscus destructans