Lecture 20

What familiar fungus structure is usually visible above ground?

A fruiting body.

In a mushroom, is the visible part generally the entire fungus?

No; it is the fruiting body.

What is the singular form of fungi?

Fungus.

What does the Latin word fungus mean?

Mushroom.

What do the fungal suffixes -mycetes and -mycota refer to?

Mushrooms or fungi.

What is mycology?

The scientific study of fungi.

Approximately how many fungal species have been described?

About 100,000 species.

What is the estimated total number of fungal species?

More than 1.5 million.

Name two non-mushroom forms of fungi.

Molds and yeasts.

Name three fungal fruiting-body examples from the overview.

Mushrooms, puffballs, and truffles.

Are fungi eukaryotic or prokaryotic?

Eukaryotic.

Why are fungi not classified as plants?

They lack chlorophyll and obtain nutrients heterotrophically.

Do fungi obtain nutrients by ingestion or absorption?

Absorption from their surroundings.

What type of nutrition characterizes fungi?

Heterotrophy.

What two environmental resources do fungi generally require?

Moisture and organic material.

Do most fungi require oxygen?

Yes.

What is an example of a facultatively anaerobic fungus?

The yeast Saccharomyces cerevisiae.

What does facultatively anaerobic mean for a fungus?

It can grow with or without oxygen.

Which major kingdom is evolutionarily closer to animals than to plants?

Fungi.

Are fungi classified in the same kingdom as plants or animals?

No; Fungi is a separate kingdom.

What major ecosystem role makes fungi essential?

Decomposition and nutrient recycling.

Name two kinds of dead organic matter fungi decompose.

Dead organisms and fallen leaves.

Which hard-to-digest plant polymer can fungi break down?

Cellulose.

What do decomposer fungi return to the environment?

Chemical nutrients other organisms can use.

Why do some insects cultivate fungus gardens?

Fungi digest cellulose that the insects cannot digest directly.

Name two insects that grow fungus gardens.

Termites and some ants.

What do termite and ant fungus gardens grow on?

Cellulose-containing material.

What kind of relationship may plants depend on fungi for?

Mutualism.

Name two food-production uses of fungi in the lecture.

Bread rising and fermentation of beer or wine.

What type of medically valuable substance can humans obtain from fungi?

Antibiotics and other drugs.

Besides food and medicine, how do scientists use fungi?

As laboratory model organisms.

What is the typical body organization of most fungi?

Multicellular, with an extensive mycelium.

What is a fungal hypha?

A filamentous, tube-like strand.

What is the plural of hypha?

Hyphae.

What is a mycelium?

An aggregate or network of hyphae.

What reproductive units do fungi commonly produce?

Spores.

Why can fungal spores survive winters or droughts?

They can be highly resistant.

What common fungi are unicellular rather than filamentous?

Yeasts.

What are mushroom-like reproductive structures of multicellular fungi called?

Fruiting bodies.

On the fungal body diagram, which network lies below the fruiting body?

Mycelium.

On the fungal body diagram, what are the threadlike filaments called?

Hyphae.

On the fungal body diagram, which structures produce reproductive spores?

Spore-producing structures on the fruiting body.

What is a fungal saprophyte?

A decomposer feeding on dead tissues or organic waste.

Which feeding lifestyle is most common in fungi?

Decomposition (saprophytic feeding).

What does a parasitic fungus take from its host?

Absorbed nutrients.

Do parasitic fungi obtain nutrients from living or dead hosts?

Living hosts.

Which organisms suffer most of the plant diseases associated with fungi?

Plants.

Can fungi cause human diseases as well as plant diseases?

Yes.

What is a mutualistic fungal symbiont?

A fungus in a relationship benefiting both partners.

How can root-associated fungi help a plant?

They improve nutrient absorption.

What does a plant generally provide to a mutualistic root fungus?

Sugars / energy-rich carbohydrates.

Are fungal lifestyles such as decomposer, parasite, and mutualist mutually exclusive?

No.

What do fungi secrete to break down dead tissues?

Powerful digestive enzymes.

What is an ecological function of fungal antibiotics?

Suppressing competing microbes.

Which medically important fungal chemicals help fight bacteria?

Antibiotics.

What fungal genus is pictured as an antibiotic example?

Penicillium.

Which intoxicating class of compounds can some fungi produce?

Hallucinogens.

What potentially dangerous compounds are produced by some fungi?

Toxins.

Which alcohol is a metabolic byproduct of some fungi?

Ethanol.

Which gas produced by fungal metabolism makes bread rise?

Carbon dioxide (CO₂).

Which fungal metabolic product is important for brewing?

Ethanol.

What is the scientific name of the fly agaric pictured in the slides?

Amanita muscaria.

What two organs are commonly damaged by highly toxic fungi?

Liver and kidneys.

Which poisonous mushroom is called the death cap?

Amanita phalloides.

Which poisonous mushroom is called the destroying angel?

Amanita virosa.

Name two highly poisonous Amanita mushrooms from class.

Death cap and destroying angel.

What is the term for light production by fungi?

Bioluminescence.

What is a likely function of fungal bioluminescence?

Attract insects that spread spores.

How might glowing fungi improve reproductive dispersal?

Attracted insects carry fungal spores.

Where do fungal hyphae elongate?

At their tips.

How do hyphae expand a mycelial network?

They grow at tips and branch extensively.

What enzymes do fungi release outside their bodies for digestion?

Exoenzymes.

Do fungi generally digest large food molecules inside or outside hyphae?

Outside, using secreted enzymes.

What is absorbed after fungal exoenzymes break down complex molecules?

Smaller nutrient products.

Which part of a hypha is pictured actively absorbing digested nutrients?

The hyphal surface.

Name the four specialized fungal forms listed in the lecture.

Molds, yeasts, lichens, and mycorrhizae.

Did specialized fungal forms evolve only once across all fungi?

No; similar adaptations evolved independently in several fungal groups.

What TWO kinds of specialization distinguish molds, yeasts, lichens, and mycorrhizae?

Morphological and ecological adaptations.

What is a mold?

A rapidly growing, multicellular fungus commonly reproducing asexually.

Do molds form mycelia?

Yes.

How can molds obtain nutrients from their substrates?

As decomposers or parasites.

What structures are produced by asexually reproducing molds?

Asexual spores.

Can some molds reproduce sexually?

Yes.

What is a yeast?

A unicellular fungus.

What kinds of habitats do yeasts commonly occupy?

Liquid or moist habitats.

Name two example habitats of yeasts from class.

Plant sap and animal tissues.

What are two common asexual reproduction methods of yeast?

Simple division and budding.

What is budding in a yeast cell?

A new cell grows out of the parent cell.

Can yeasts reproduce sexually?

Yes; some can.

Which yeast genus is pictured in the lecture?

Saccharomyces.

What is a lichen?

A fungus associated with photosynthetic microorganisms.

What fungal structures form the mesh in a lichen?

Hyphae.

Name two possible photosynthetic lichen partners.

Green algae or cyanobacteria.

What does the fungal partner supply in a lichen?

Structure, protection, and absorption.

What does the photosynthetic partner supply in a lichen?

Nutrients from photosynthesis.

How is a lichen classified despite having different symbiotic partners?

As a single species.

What organism is commonly called “reindeer moss”?

A shrub-like lichen.

What is the scientific name of reindeer moss?

Cladonia rangiferina.

Is reindeer moss a true moss?

No; it is a lichen.

Why can lichens indicate local air quality?

Many species are sensitive to pollution.