Mycology Quiz Questions

Paecilomyces sp. is known for its similar conidiophore morphology to Penicillium sp. and is not a common cause of opportunistic infections, unlike Aspergillus sp., Fusarium sp., and Alternaria sp.

Fungi are distinct from plants and animals due to their unique characteristics and methods of reproduction.

The structure shown in the image corresponds to arthroconidia based on its morphology under the microscope. Blastoconidia, chlamydospores, and ascospores are different structures with distinct characteristics in yeast cultures.

Aspergillus sp. is known for its unique characteristics including foot cells, swollen vesicles, hyaline septate hyphae, and uniseriate or biseriate conidiation. The other options do not exhibit all of these specific features.

Differentiation of Zygomycetes is primarily based on the presence and location of rhizoids (root-like hyphae) and the type of sporangiophore (structure that bears sporangia). Other characteristics mentioned in the incorrect answers do not play a significant role in the differentiation of Zygomycetes.

Budding is the process of reproduction in yeast where a new cell grows from the surface of the parent cell. Fission, germination, and fragmentation are not the correct terms to describe this specific process.

Conidia are the asexual reproductive structures of molds, whereas Sporangia, Ascospores, and Basidiospores are associated with other types of fungi reproductive structures.

The correct answer is Microsporum canis, as it is known to cause a woods lamp positive dermatophytic infection and is typically identified using lactophenol cotton blue stain on a tease prep. Trichophyton rubrum, Epidermophyton floccosum, and Microsporum gypseum are also common dermatophytes but are not the most likely identification under the given conditions.

Blastoconidia are a type of asexual spore produced by budding yeast cells. Hyphae, ascospores, and chlamydospores are not typically found in yeast cultures.

Epidermophyton floccosum typically produces pleomorphic, white tufts of aerial hyphae as the colony aged when grown in the laboratory and stained with lactophenol cotton blue. Trichophyton rubrum is not associated with the described characteristics. Microsporum canis is more known for producing large, round, greenish colonies with hyphae that fluoresce under UV light. Tinea versicolor is not a dermatophyte but rather a yeast, Malassezia furfur, that causes a skin condition characterized by discolored patches.

Chlamydoconidia are spores produced by the rounding up and enlargement of the terminal cells of hyphae. Basidiospores, ascospores, and zygospores are produced through different mechanisms and structures in fungal reproduction.

Macroconidia are large spores that are usually multiseptate and club- or spindle-shaped. Microconidia are smaller spores, ascospores are spores produced in asci within ascocarps, and basidiospores are spores produced in basidia on basidiocarps.

The correct identification of the organism based on the given microscopic morphology is Fusarium sp. as it matches the characteristics of the macroconidia found in Fusarium species. Aspergillus sp., Candida sp., and Penicillium sp. have different macroconidia morphology that would not match the description provided.

The correct method for tease/cut preparation involves directly removing the organism from the culture plate and transferring it to a microscope slide for examination.

The term dematiaceous specifically refers to the presence of pigmentation within the hyphae or the spores of certain fungi.

The correct answer describes the characteristics of the genus Epidermophyton with precise details about the shape, size, septations, presence of microconidia, and chlamydoconidia. The incorrect answers provide descriptions that do not align with the actual characteristics of the genus, making them incorrect choices. Each incorrect answer can be ruled out based on their deviations from the accurate depiction of Epidermophyton.

Aspergilloma is characterized by the presence of a fungal ball growing within a preexisting lung cavity. It differs from lung consolidation, pleural effusion, and cavitation without fungal ball formation.

Microscopic morphologic features provide more specific and reliable information for identifying clinically significant moulds compared to other factors such as color, size, or geographic location.

The term 'hyaline' specifically refers to a characteristic of molds, not glass, weather phenomena, or fish species.

Pseudallescheria boydii fits the description given in the question including the key features such as SABHI medium growth, hyaline appearance, and characteristics of its septate hyphae. Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans do not match the description provided and do not typically exhibit the same features as Pseudallescheria boydii in the clinical scenario described.

Microsporum canis is the most likely organism due to its characteristic features mentioned in the question. The other options are common dermatophytes as well but do not match the given description.

Mycelium is the correct term for the network of structural units of moulds. Hyphae are the thread-like filaments that make up the mycelium, while spores are reproductive cells. Rhizoids are root-like structures found in some fungi but are not the primary network for nutrient absorption.

Zygomycetes are known for their rapid growth in laboratory settings, making it one of their distinct characteristics compared to other fungi.

Negative staining is a technique used to visualize capsules surrounding bacteria. Encapsulated cells will appear clear against a dark background due to the negative stain, while structures like flagella, biofilms, and spores will not be highlighted in this manner.

Malassezia furfur is a lipophilic yeast that is commonly found on the skin. Candida albicans is a common yeast that does not have the same lipophilic properties. Cryptococcus neoformans is a pathogenic yeast that is not considered lipophilic. Aspergillus fumigatus is a mold, not a yeast, and is not lipophilic.

Penicillium sp. is the correct answer because of its unique microscopic morphology, including its branching, flask-shaped conidiophores. The other options do not exhibit the same characteristics as Penicillium sp.

White piedra is a fungal infection of the hair shaft caused by Trichosporon spp. Candida albicans, Malassezia furfur, and Epidermophyton floccosum are not known to be associated with white piedra.