General Mycology Quiz

Fungi are eukaryotic organisms that differ from bacteria in their cell wall composition, cell membrane structure, and nuclear organization.

Chitin, a polysaccharide found in fungal cell walls, provides structural support and is not affected by antibiotics.

Ergosterol, a sterol found in fungal cell membranes, is the target of many antifungal drugs like amphotericin B and azoles.

Yeasts are single-celled fungi that reproduce asexually by budding, while molds are multicellular fungi that grow as filaments called hyphae, forming a network called mycelium.

Septate hyphae have cross-walls separating individual cells, while nonseptate hyphae are multinucleated without cross-walls.

Medically important fungi can exhibit dimorphism, meaning they can switch between different growth forms depending on the temperature.

Fungi can have beneficial roles, such as producing antibiotics, fermenting carbohydrates, decomposing dead organisms, and serving as food sources in some societies.

Fungi can cause harmful effects, such as food spoilage, production of mycotoxins (toxins produced by fungi), and diseases (mycotoxicosis) in humans and animals.

Fungi can grow in a wide range of temperatures, but pathogenic fungi thrive in temperatures between 20-40°C, which is considered the mesophilic range.

Most fungi need oxygen to survive and are considered obligate aerobes. However, some fungi can survive without oxygen and are called facultative anaerobes. No fungi can solely survive without oxygen.

Fungi obtain their energy from preformed organic sources, often associated with decaying matter. Fungi are key to decomposition in the environment.

Asexual reproduction is a common method for fungi, where a parent fungus produces a copy of itself without the need for mating. Asexual reproduction in fungi often involves the formation of conidia.

Zygospores are a type of sexual spore formed by fungi in the Phycomycete group. These spores are large and have thick walls.

Ascospores are a type of sexual spore formed by fungi in the Ascomycete group. They are formed within a sac-like structure called an ascus.

Basidiospores are formed externally on a pedestal-like structure called a basidium. These fungi do not reproduce asexually and are not typically pathogenic to humans.

Immune responses to fungal infections often involve the formation of granulomas, which are clusters of immune cells that try to wall off the infection. Granulomas are a hallmark of many systemic fungal diseases like coccidioidomycosis, histoplasmosis, and blastomycosis.

A type of fungal infection where neutrophils are present in the exudate.

A skin test that checks for exposure to fungal antigens. A positive result means exposure, but not necessarily current infection.

A common fungus that lives on skin as normal flora. Skin tests for Candida are used to assess cell-mediated immunity.

The body's primary defense against fungal infections. Intact skin prevents fungal entry.

Fungal toxins produced by some species of fungi, including those that can cause liver damage.

A fungal toxin produced by Amanita mushrooms, known to cause severe liver damage.

A condition caused by the toxins produced by the Claviceps purpurea fungi, leading to vascular and neurological problems.

A fungal toxin produced by Aspergillus flavus, linked to liver cancer.

Directly examining clinical specimens under a microscope to identify characteristic fungal structures like spores, hyphae, or yeasts. Typical staining methods include KOH, India ink, fluorescent dyes, or Methenamine silver.

Cultivating fungi on Sabouraud's agar, a medium that inhibits bacterial growth due to its low pH and addition of anti-bacterial agents like chloramphenicol and cycloheximide.

Utilizing DNA probes to rapidly identify fungal colonies in culture, even at early stages of growth.

Testing patient serum or spinal fluid for the presence of antibodies, particularly useful for diagnosing systemic fungal infections. Significant rise in antibody titer confirms the diagnosis.

A diagnostic test used to detect the presence of specific polysaccharide capsular antigens of Cryptococcus neoformans in spinal fluid, primarily used in cases of cryptococcal meningitis.