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Part V: Mycology
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Regarding the structure and reproduction of fungi, which one of the following is most accurate?
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(A) Peptidoglycan is an important component of the cell wall of fungi.
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(B) Molds are fungi that grow as single cells and reproduce by budding.
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(C) Some fungi are dimorphic (i.e., they are yeasts at room temperature and molds at body temperature).
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(D) The fungal cell membrane contains ergosterol, whereas the human cell membrane contains cholesterol.
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(E) As most fungi are anaerobic, they should be cultured under anaerobic conditions in the clinical laboratory.
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Regarding fungal pathogenesis, which one of the following is most accurate?
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(A) Ingestion of Amanita mushrooms typically causes kidney failure.
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(B) The host response to infection by the systemic fungi, such as Histoplasma and Coccidioides, consists of granulomas formation.
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(C) The fever seen in systemic fungal infections is caused by endotoxin-induced release of interlukin-1.
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(D) Ingestion of aflatoxin produced by Aspergillus flavus can cause adenocarcinoma of the colon.
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(E) A positive result in the skin test to fungal antigens, such as coccidioidin, is caused by an immediate hypersensitivity reaction.
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Regarding the mode of action of antifungal drugs, which one of the following is most accurate?
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(A) Azole drugs, such as fluconazole, act by inhibiting ergosterol synthesis.
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(B) Amphotericin B acts by inhibiting fungal protein syntheses at the 40S ribosomal subunit.
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(C) Terbinafine acts by inhibiting fungal DNA synthesis but has no effect on DNA synthesis in human cells.
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(D) Echinocandins, such as caspofungin, act by inhibiting messenger RNA synthesis in yeasts but not in molds.
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The selective toxicity of amphotericin B is based on the presence in fungi of which one of the following?
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(A) 30S ribosomal subunit
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(B) Dihydrofolate reductase
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Regarding ringworm and the dermatophytes, which one of the following is most accurate?
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(A) The dermatophytes are molds and are not thermally dimorphic.
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