Fungi

What domain do fungi belong to?

Domain Eukarya.

What kingdom do fungi belong to?

Kingdom Fungi.

Are fungi prokaryotic or eukaryotic?

Eukaryotic because they have a true nucleus and membrane-bound organelles.

What are the two major forms of fungi?

Yeasts and molds.

What are yeasts?

Unicellular fungi that reproduce primarily by budding.

What are molds?

Multicellular, filamentous fungi composed of hyphae.

What is dimorphism in fungi?

The ability of some fungi to exist as both yeast and mold depending on environmental conditions, especially temperature.

At what temperature do many dimorphic fungi grow as molds?

Approximately 25°C.

At what temperature do many dimorphic fungi grow as yeasts?

Approximately 37°C.

What does anamorphic mean?

The asexual reproductive stage of a fungus.

What does teleomorphic mean?

The sexual reproductive stage of a fungus.

What is a hypha?

A long, thread-like fungal filament.

What is a mycelium?

A mass or network of hyphae that forms the body of a mold.

What is a thallus?

The vegetative body of a fungus.

What is the difference between septate and coenocytic hyphae?

Septate hyphae have cross-walls (septa); coenocytic hyphae lack septa and are continuous.

What are vegetative hyphae?

Hyphae responsible for nutrient absorption and growth.

What are reproductive hyphae?

Hyphae that produce spores used for reproduction.

How do fungi obtain nutrients?

By secreting digestive enzymes and absorbing the digested nutrients.

What is the main component of the fungal cell wall?

Chitin.

How do fungi reproduce asexually?

By budding, fragmentation, or production of asexual spores.

How do fungi reproduce sexually?

By fusion of compatible nuclei followed by formation of sexual spores.

Which yeast species was observed in lab and is an opportunistic pathogen?

Candida albicans.

Which yeast species is commonly used in baking and brewing?

Saccharomyces cerevisiae.

How does Candida albicans reproduce?

Primarily by budding.

How does Saccharomyces cerevisiae reproduce?

Primarily by budding.

What is budding?

A form of asexual reproduction in which a new cell grows from the parent cell.

Which fungal group produces zygospores sexually and sporangiospores asexually?

Zygomycetes.

Which organism was used as the example of a zygomycete?

Rhizopus stolonifer (bread mold).

What type of hyphae does Rhizopus have?

Coenocytic (non-septate) hyphae.

What structure contains sporangiospores in Rhizopus?

The sporangium.

What is a sporangium?

A sac-like structure that contains asexual spores.

What are sporangiospores?

Asexual spores produced inside a sporangium.

What is a zygospore?

A thick-walled sexual spore produced by zygomycetes.

Which fungal group includes Aspergillus and Penicillium?

Ascomycetes.

What type of hyphae do Aspergillus and Penicillium have?

Septate hyphae.

How does Aspergillus reproduce asexually?

By producing chains of conidia on specialized hyphae called conidiophores.

What are conidia?

Asexual spores produced externally on conidiophores.

What is a conidiophore?

A specialized reproductive hypha that bears conidia.

How can Aspergillus be recognized microscopically?

It has a swollen conidiophore ending with chains of conidia that resemble a dandelion or radiating sphere.

How can Penicillium be recognized microscopically?

It has brush-like clusters of conidiophores with chains of conidia.

Why is Penicillium medically important?

It is the source of the antibiotic penicillin.

What is the difference between sporangiospores and conidia?

Sporangiospores are enclosed within a sporangium, while conidia are exposed on conidiophores.

What fungal characteristic helps distinguish Rhizopus from Aspergillus?

Rhizopus has non-septate hyphae and sporangia, while Aspergillus has septate hyphae and conidia.

Why are fungi considered heterotrophs?

They cannot produce their own food and absorb nutrients from organic material.

Why are fungi important medically?

They can cause infections, allergies, and produce antibiotics and toxins.

Which organism would you identify if you observed budding yeast cells?

Candida albicans or Saccharomyces cerevisiae.

Which organism would you identify if you observed large round sporangia on non-septate hyphae?

Rhizopus stolonifer.

Which organism would you identify if you observed brush-like conidiophores?

Penicillium.

Which organism would you identify if you observed radiating chains of conidia from a swollen tip?

Aspergillus.

What microscopic feature distinguishes molds from yeasts?

Molds have multicellular hyphae, while yeasts are unicellular and reproduce by budding.

Why is dimorphism considered a virulence factor?

It allows pathogenic fungi to adapt to different environments within the host.