Fungal Structure, Nutrition & Cytology
What structural polysaccharide composes the rigid cell walls of all true fungi?
C) Chitin
What does it mean if a fungal hypha is described as dikaryotic (n+n)?
Which fungal phylum contains aquatic, predominantly unicellular species that produce motile zoospores with single posterior flagella, including Batrachochytrium dendrobatidis (causing amphibian chytridiomycosis)?
C) Chytridiomycota
A lichen is a mutualistic symbiotic association between a fungus (usually an Ascomycete) and which photosynthetic partner(s)?
B) Green algae or cyanobacteria
Fungi are primary ecological decomposers (saprobes). What two complex, tough organic polymers in plant cell walls are fungi uniquely capable of enzymatically breaking down?
Fungi consist of microscopic thread-like filaments called hyphae. What is the term for a woven mass of interconnected hyphae forming the body of a fungus?
A) Mycelium
Sexual reproduction in fungi involves two distinct fusion events separated in time. What are the names of cytoplasmic fusion and nuclear fusion, respectively?
B) Plasmogamy (cytoplasm) and Karyogamy (nuclei)
Black bread mold (Rhizopus) belongs to Phylum Zygomycota. What thick-walled, rough-coated structure is produced during sexual reproduction when two compatible hyphae fuse?
C) Zygosporangium
Lichens are categorized into three growth forms based on appearance. Which option correctly matches the growth form with its description?
A) Fruticose = Shrubby/branched; Foliose = Leaf-like; Crustose = Flattened/crust-like
Baker's and brewer's yeast (Saccharomyces cerevisiae) is a unicellular fungus belonging to Ascomycota. How does it reproduce asexually, and what metabolic process drives bread rising and alcohol production?
Fungi obtain nutrients through absorptive heterotrophy. How does this process function mechanically?
B) By secreting digestive enzymes externally into their surroundings and absorbing the breakdown products
What is the correct chronological sequence of events in the fungal sexual life cycle?
Mushrooms, puffballs, shelf fungi, and rusts belong to Phylum Basidiomycota. What is their diagnostic sexual reproductive structure, and how many spores does it typically bear externally?
B) A club-shaped basidium bearing 4 external basidiospores
Arbuscular Mycorrhizae (Glomeromycota) differ structurally from Ectomycorrhizae (mostly Basidiomycota) in how they interact with plant root cells. What is this structural distinction?
A) Arbuscular hyphae penetrate plant root cell walls; Ectomycorrhizae surround root cells without cell wall penetration
What dangerous carcinogenic mycotoxins are produced by Aspergillus species growing on improperly stored grains and peanuts, posing severe liver damage risks to humans and livestock?
Why are systemic fungal infections in humans significantly harder to treat clinically than bacterial infections?
How do heterokaryotic hyphae differ from homokaryotic hyphae?
A) Heterokaryotic hyphae contain genetically distinct haploid nuclei; Homokaryotic hyphae contain genetically identical haploid nuclei
Phylum Ascomycota ("sac fungi") includes cup fungi, truffles, morels, and yeasts. What is the microscopic, sac-like sexual structure that encloses haploid ascospores, and how many spores are typically produced inside it?
B) An ascus containing 8 ascospores
Endophytic fungi live inside the intercellular spaces of healthy plant stems and leaves. How do endophytes benefit their host plant?
B) They produce toxic alkaloids that deter herbivores and increase drought tolerance
Which revolutionary antibiotic drug was famously discovered by Alexander Fleming when he noticed a green mold contaminating his bacterial culture plates and inhibiting bacterial growth?
Fungi undergo an unusual form of intranuclear mitosis. How does fungal mitosis differ from typical plant and animal cell division?
Septate hyphae are divided into cell-like compartments by cross-walls called septa. What important structural feature do these septa possess?
B) Pores large enough to allow cytoplasm, organelles, and sometimes nuclei to flow between cells
Which of the following correctly pairs a minor/specialized fungal phylum with its characteristic feature?
A) Neocallimastigomycota: Anaerobic fungi living in herbivore rumens that digest cellulose using multi-flagellated zoospores
Claviceps purpurea is an Ascomycete fungus that infects rye and cereal grains, producing toxic alkaloid sclerotia. What historical human illness—characterized by hallucinations, gangrene, and convulsions—is caused by consuming flour contaminated with this fungus?
B) Ergotism
Mushrooms in Basidiomycota use a high-speed liquid discharge mechanism to forcibly launch basidiospores off their sterigmata into surrounding air currents. What is this surface-tension catapult mechanism called?