Skip to main content
Back

Microbiology: Molds and Fungal Structures

Control buttons has been changed to "navigation" mode.
1/20

Terms in this set (20)

  • What are molds?

    Molds are multicellular fungi composed of filamentous structures called hyphae that form a network called mycelium.

  • What are hyphae and mycelium?

    Hyphae are individual thread-like filaments of a mold, and mycelium is the mass or network of hyphae.

  • Difference between vegetative mycelium and aerial mycelium

    Vegetative mycelium grows on or in the substrate absorbing nutrients, while aerial mycelium grows above the substrate and is involved in reproduction.

  • What is the cell wall of molds composed of?

    The cell wall of molds is primarily composed of chitin, a polysaccharide.

  • How do molds reproduce?

    Molds reproduce by forming spores, which can be asexual or sexual spores.

  • What are conidia?

    Conidia are asexual, non-motile spores produced by molds on specialized hyphae called conidiophores.

  • What are the asexual reproductive spores of molds called?

    The asexual reproductive spores of molds are called conidia.

  • How are common molds classified?

    Common molds are classified based on their spore types and reproductive structures, such as conidia or sporangiospores.

  • Examples of common molds that produce conidia

    Examples include Penicillium and Aspergillus.

  • What are phialides and conidiophores?

    Conidiophores are specialized hyphae that bear conidia; phialides are flask-shaped cells on conidiophores that produce conidia.

  • Different structures found on Aspergillus hypha

    Aspergillus hyphae have conidiophores ending in a vesicle with phialides that produce chains of conidia.

  • What diseases does Aspergillus cause?

    Aspergillus can cause aspergillosis, a respiratory infection, especially in immunocompromised individuals.

  • What are sporangiospores and which mold produces them?

    Sporangiospores are asexual spores produced inside a sac called a sporangium; Rhizopus produces sporangiospores.

  • What diseases can Rhizopus cause?

    Rhizopus can cause mucormycosis, a serious fungal infection affecting sinuses, brain, and lungs.

  • What are dermatophytes and what is ringworm?

    Dermatophytes are fungi that infect skin, hair, and nails; ringworm is a common dermatophyte infection causing circular skin lesions.

  • How are dermatophyte infections diagnosed?

    Diagnosis is by microscopic examination of skin scrapings and culture on selective media.

  • What medium is used to culture fungi from infected tissue?

    Dermatophyte Test Medium (DTM) is used to culture fungi from infected tissue.

  • What are macroconidia and microconidia?

    Macroconidia are large, multicellular asexual spores; microconidia are smaller, unicellular spores produced by dermatophytes.

  • What does DTM contain and its pH changes?

    DTM contains nutrients and a pH indicator; initial pH is acidic (~6.8), and it turns alkaline (red) after dermatophyte growth due to protein metabolism.

  • What do dermatophytes use to grow in DTM?

    Dermatophytes use keratin in DTM as a nutrient source, causing pH changes.