L21: Intro to Medical Mycology

Question 1

True or False: Fungi are prokaryotic and autotrophic

Answer 1

False - eukaryotic and heterotrophic (lack chlorophyll)

Question 2

Fungi can either be parasites or saprophytes. What is the difference between the two?

Answer 2

Parasites: use living tissue
Saprophytes: live on dead organic matter

Question 3

The fungal cell wall is rigid and non-motile. They also contain polysaccharides, such as ___ and ___, glycoproteins, and lipids

Answer 3

chitin and glucans

Question 4

____ is found in the lipid bilayer of the fungi cell membrane
A. Chitin
B. Ergosterol
C. Cholesterol

Answer 4

B. Ergosterol

Question 5

Which of the following are molds?
A. Cryptococcus
B. C. albicans
C. Aspergillus

Answer 5

C. Aspergillus

Question 6

Which of the following is NOT a yeast?
A. C. albicans
B. Cryptococcus
C. M. furfur
D. Microsporum

Answer 6

D. Microsporum

Question 7

True or False: Microsporum, Epidermophyton, and Trichophyton are all Dermatophytes

Answer 7

True

Question 8

Histoplasma
Blastomyces
Coccidiodes
Sporothrix
belong to which two groups?
A. Yeast / superficial
B. Mold
C. Dimorphic Fungi / systemic
D. Dermatophytes

Answer 8

C. Dimorphic Fungi / systemic

Question 9

True or False: Sporothrix is a subcutaneous mycoses, as well as a Dimorphic Fungi

Answer 9

True

Question 10

True or False: Microsporum, Epidermophyton, and Trichophyton are both dematophytes / cutaneous mycoses

Answer 10

True

Question 11

Name four opportunistic mycoses:

Answer 11

1. C. albicans
2. P. jirovecii
3. Cryptococcus
4. Aspergillus

Question 12

You are looking at growth on an agar plate, which has colonies that appear smooth, round, and white.
What is it?
A. Mold
B. Yeast - unicellular
C. Filamentous Fungi

Answer 12

B. Yeast
- unicellular fungi

Question 13

How to yeast reproduce? Form?
A. Sexually
B. Asexually

Answer 13

B. Asexually
- budding
- form blastoconidia (blastophores)

Note: some yeast do reproduc sexually, forming ascospores or basidiospores

Question 14

Yeast can form blastoconidia, which may elongate and form ___ or ___

Answer 14

hyphae or pseudohyphae

Question 15

____: Elongated buds that have failed to separate, connected to one another to create a “link’s of
sausage” appearance (number of blastoconidia that remain
attached). Have cell wall constrictions, rather
than true intracellular septations
A. Hyphae
B. Pseudohyphae
C. Germ Tube

Answer 15

B. Pseudohyphae

Question 16

___: Tubular outpouching without constriction at its
base; this is the initial stage of true hyphae formation
A. Hyphae
B. Pseudohyphae
C. Germ Tube

Answer 16

C. Germ Tube

Question 17

____: A screening test used to differentiate C. albicans from other yeast. It is (+) for C. albicans and C. dubliniensis

Answer 17

Germ Tube Test

Question 18

____ is an example of an encapsulated, budding yeast

Answer 18

Cryptococcus

Question 19

True or False: When grown on an agar plate, molds (multi-cellular fungi) appear fuzzy, fluffy, and powdery

Answer 19

True

Question 20

___: Tubular structures formed by fungi

_____: A mass of hyphae

Answer 20

hyphae; mycelium

Question 21

True or False: Molds reproduce via spore formation (either sexually or asexually)

Answer 21

True

Question 22

Which of the following is a yeast at body temperature (parasitic phase) and a mold at room temperature (saprobic phase)?
A. C. Albicans/Cryptococcus
B.Histoplasma/Blastomyces
C.Microsporum/ Trichophyton
D. Sporothrix

Answer 22

D. Sporothrix
B.Histoplasma/Blastomyces

• All of which are dimorphic fungi

Question 23

Answer 23

Question 24

Which of the is the selective media for fungi?
A. Chocolate Agar
B. Sabouraud Dextrose Agar
C. Wood’s Lamp UV
D. Dermatophyte Test Media

Answer 24

B. Sabouraud Dextrose Agar

Question 25

True or False: Wood’s Lamp UV Light is used to examine fungi of the underside pigment–specifically the skin and the hair–and is used to determine prognosis of diseases

Answer 25

True

Question 26

True or False: Both the Periodic Acid Schiff (PAS) stain and the Grocott’s Methnamine Silver (GMS) stain carbohydrates found in yeast

Answer 26

False - carbohydrates found in fungi

Question 27

Which stain is most apt for rapid diagnosis of fungal cell wall?
A. Gram Stain
B. Fluorescent Ab Stain
C. GAS Stain
D. PAS Stain

Answer 27

B. Fluorescent Ab Stain

Question 28

10% KOH dissolves keratin and cellular debris and, therefore, is used to…
A. Visualize fungal hyphae
B. Visualize fungi from hair/nail specimens
C. Used to look at dermatophytes

Answer 28

B. Visualize fungi from hair/nail specimens

Question 29

True or False: Lactophenol cotton blue is used to visualize hyphae

Answer 29

True

Question 30

Which of the following is used to detect capsule of Cryptococcus?
A. India Ink
B. Calcofluor White stain
C. Gram strain
D. Lactophenol Cotton Blue

Answer 30

A. India Ink

Question 31

Which of the following binds to the chitin in the cell walls of the fungi, allowing for the visualization of fungi?
A. India Ink
B. Calcofluor White stain
C. Gram strain
D. Lactophenol Cotton Blue

Answer 31

B. Calcofluor White stain

Question 32

Histoplasma, Blastomyces, and Coccidiodes are examples of…
A. True Fungi
B. Opportunistic Fungi

Answer 32

A. True Fungi

Question 33

Candida, Aspergillus, Cryptococcus are examples of…
A. True Fungi
B. Opportunistic Fungi

Answer 33

B. Opportunistic Fungi