Biodiversity 4 Flashcards

A set of 50 flashcards based on a lecture about the biodiversity of fungi, highlighting key concepts, relationships, and functions of fungi within the Opisthokont clade.

What are the key synapomorphies that unite all fungi?

Chitin in the cell wall and absorptive heterotrophy.

What unites the clade of Opisthokonts?

A single posterior flagellum.

How are fungi related to choanoflagellates and animals?

They share a common ancestor that was unicellular with a single posterior flagellum.

What is absorptive heterotrophy?

A process where fungi secrete enzymes to digest organic materials and absorb nutrients.

What is the main mass of hyphae in fungi called?

Mycelium.

What structure does a fruiting body represent in fungi?

The part of the fungus that is visible above ground, reproducing spores.

How do plants defend against fungal infections?

By producing an enzyme called chitinase that breaks down chitin in fungal cell walls.

What is the relationship between plants and arbuscular mycorrhizae?

They form a symbiotic relationship where fungi absorb nutrients for the plant and receive sugars in return.

What are microsporidia?

Small, unicellular, parasitic fungi with reduced mitochondria and a polar tube for infecting host cells.

What group of fungi is known for having flagellated gametes?

Chytrids.

What type of fungi are known for their pathogenic effects on amphibians?

Chytrids.

What is the dikarya?

A group of fungi that includes ascomycota and basidiomycota characterized by a dikaryon stage with two nuclei.

What do ascomycota produce their spores in?

An ascus.

What do basidiomycota produce their spores on?

A basidium.

What common use do yeasts, a type of ascomycota, have?

They are used in making alcohol and bread.

What are lichens composed of?

A mutualistic symbiosis between a fungus and a green algae or cyanobacterium.

Why are lichens considered pioneer organisms?

They can colonize extreme environments and are often the first organisms to appear after disturbances.

How do saprobic fungi obtain nutrients?

By breaking down non-living organic matter as decomposers.

What lifestyle do some fungi have that involves capturing prey?

Predatory fungi use mechanisms to trap and digest nematodes.

What is a well-known type of parasitic fungus affecting plants?

Rusts and smuts.

How do most fungi reproduce?

Fungi can reproduce both asexually and sexually.

What is the significance of septate hyphae in dikarya?

It allows for controlled movement of nutrients and organelles within the fungal body.

What can fungal diseases affect in humans?

They can cause various infections such as athlete's foot and ringworm.

What is a unique feature of the dikarya's life cycle?

The dikaryon stage, where two hyphae from different strains fuse.

What role do fungi play in culinary applications?

They are used in producing soy sauce, sake, and cheese.

How do chitin and its associated enzyme play a role in plant-fungal interactions?

Plants produce chitinase to combat fungal infections by degrading fungal cell walls.

What is the primary purpose of the mycelium in fungi?

To absorb nutrients and facilitate growth.

What evolutionary significance do multicellularity in fungi and animals have?

Fungi and animals evolved multicellularity independently from a unicellular ancestor.

What are the physical characteristics of fungi classified under microsporidia?

They have reduced mitochondria and a polar tube for infection.

How do fungi like lichens adapt to extreme environments?

They can tolerate heat, cold, and aridity, allowing them to thrive as pioneers.

What is the evolutionary importance of the Cambrian explosion in relation to fungi?

Most large fungi evolved after the Cambrian explosion, showcasing a timeline of diversification.

What type of relationships do fungi have with plants through arbuscular mycorrhizae?

They form mutualistic symbioses, enhancing nutrient uptake for plants.

What is the function of the hyphae in fungi?

To absorb nutrients and facilitate growth in the mycelium.

What are the two main groups within the dikarya?

Ascomycota and basidiomycota.

What ecological role do saprophytic fungi play?

They decompose dead organic matter, recycling nutrients back into the ecosystem.

What does the term 'absorptive heterotrophy' imply about fungi?

That they secrete enzymes to digest food externally and absorb resulting nutrients.

Which fungi are notable for their ability to capture nematodes?

Predatory fungi.

What do the structures of basidia in basidiomycota resemble?

Clubs.

What is an example of a disease caused by parasitic fungi in humans?

Athlete’s foot.

What distinguishes the reproductive spores of ascomycota from those of basidiomycota?

Ascomycota release spores from a structure called an ascus while basidiomycota spores fall off from a basidium.

What is a significant effect of chytrid fungi on amphibians?

They may lead to the extinction of certain amphibian species.

How can rusts and smuts affect agriculture?

They are known pathogens that disrupt crop health.

What is the integral term used for single-celled fungi?

Yeast.

What are animals in the context of Opisthokonts?

Multicellular eukaryotes that, along with fungi and choanoflagellates, belong to the Opisthokont clade, sharing a common unicellular ancestor with a single posterior flagellum.

What are arbuscular mycorrhizal fungi?

Fungi that form a mutualistic symbiotic relationship with plants, absorbing nutrients for them and receiving sugars in return, characterized by tree-like (arbuscular) structures within plant root cells.

What is Ascomycota?

A diverse phylum of fungi (sac fungi) within the Dikarya, characterized by producing sexual spores (ascospores) in a sac-like structure called an ascus. This group includes yeasts, truffles, and morels.

What is Basidiomycota?

A phylum of fungi (club fungi) within the Dikarya, characterized by producing sexual spores (basidiospores) externally on club-shaped structures called basidia. This group includes mushrooms, puffballs, and shelf fungi.

What are Chytrids?

Early-diverging fungi characterized by flagellated gametes (zoospores) and often found in aquatic environments. Some species are well-known pathogens of amphibians.

What is the Dikarya?

A major clade of fungi that includes Ascomycota and Basidiomycota, characterized by a dikaryon stage (n+n) in their life cycle where two haploid nuclei coexist within the same cell before fusion.

What are fungi?

Eukaryotic organisms that are absorptive heterotrophs, typically possessing cell walls made of chitin, and often growing as filamentous structures called hyphae.

What are lichens?

A mutualistic symbiotic organism composed of a fungus (usually an Ascomycete) and a photosynthetic partner (either a green alga or a cyanobacterium), known for colonizing extreme environments.

What are Microsporida?

A group of small, unicellular, parasitic fungi with reduced mitochondria and a unique polar tube mechanism used to infect host cells.

What are Opisthokonts?

A supergroup of eukaryotes that includes animals, fungi, and choanoflagellates, all unified by the presence of a single posterior flagellum at some point in their life cycle.

What is Saccharomyces\ cerevisiae?

A species of yeast (a single-celled Ascomycota) widely used in baking and brewing due to its ability to ferment sugars into alcohol and carbon dioxide.

What is an absorptive heterotroph?

An organism that obtains nutrients by secreting digestive enzymes onto organic material outside its body and then absorbing the broken-down molecules. This is the primary feeding strategy of fungi.

What is an ascus?

A sac-like microscopic structure unique to Ascomycota fungi, within which sexual spores (ascospores) are produced and contained.

What is a basidium?

A club-shaped, microscopic spore-bearing structure unique to Basidiomycota fungi, typically producing four sexual spores (basidiospores) externally.

What does dikaryotic (n+n) mean in fungi?

A condition in the fungal life cycle, particularly in Dikarya, where each cell contains two genetically distinct haploid nuclei (one from each parent) that have not yet fused.

What is chitin in fungi?

A tough, structural polysaccharide that forms the primary component of the cell walls in fungi, providing rigidity and protection.

What are hyphae?

Thread-like, filamentous structures that are the fundamental building blocks of most fungi, responsible for growth, nutrient absorption, and forming the mycelium.

What is a mycelium?

The main body of a fungus, consisting of an interwoven mass of branched, tubular hyphae, primarily responsible for nutrient absorption and often growing underground or within a substrate.

What is a fungal fruiting structure (or fruiting body)?

The visible, above-ground reproductive part of a fungus, typically producing and dispersing spores, such as a mushroom.

What are mating types in fungi?

Genetically determined compatibility groups in sexually reproducing fungi that prevent self-fertilization and ensure genetic diversity by requiring compatible types to mate.

What are mycorrhizae?

A broad term for a mutualistic symbiotic association between a fungus and the roots of a plant, where the fungus helps the plant absorb water and nutrients, and the plant provides sugars to the fungus.

What is a fungal parasite?

A fungus that lives on or in another organism (the host) and obtains nutrients from it, typically causing harm to the host.

What is a fungal saprobe (or saprophyte)?

A fungus that obtains nutrients by decomposing dead organic matter, playing a crucial role as a decomposer in ecosystems.

What is symbiosis in the context of fungi?

A close and long-term biological interaction between two different biological organisms, which can be mutualistic (both benefit), commensalistic (one benefits, other neutral), or parasitic (one benefits, other harmed).

What are the key synapomorphies that unite all fungi?

Chitin in the cell wall and absorptive heterotrophy.

What is chitin in fungi?

A tough, structural polysaccharide that forms the primary component of the cell walls in fungi, providing rigidity and protection.

What is an absorptive heterotroph?

An organism that obtains nutrients by secreting digestive enzymes onto organic material outside its body and then absorbing the broken-down molecules. This is the primary feeding strategy of fungi.

What are Opisthokonts?

A supergroup of eukaryotes that includes animals, fungi, and choanoflagellates, all unified by the presence of a single posterior flagellum at some point in their life cycle.

How are fungi related to choanoflagellates and animals?

They share a common ancestor that was unicellular with a single posterior flagellum.

What are arbuscular mycorrhizal fungi?

Fungi that form a mutualistic symbiotic relationship with plants, absorbing nutrients for them and receiving sugars in return, characterized by tree-like (arbuscular) structures within plant root cells.

What is Ascomycota?

A diverse phylum of fungi (sac fungi) within the Dikarya, characterized by producing sexual spores (ascospores) in a sac-like structure called an ascus. This group includes yeasts, truffles, and morels.

What is Basidiomycota?

A phylum of fungi (club fungi) within the Dikarya, characterized by producing sexual spores (basidiospores) externally on club-shaped structures called basidia. This group includes mushrooms, puffballs, and shelf fungi.

What are Chytrids?

Early-diverging fungi characterized by flagellated gametes (zoospores) and often found in aquatic environments. Some species are well-known pathogens of amphibians.

What is the Dikarya?

A major clade of fungi that includes Ascomycota and Basidiomycota, characterized by a dikaryon stage (n+n) in their life cycle where two haploid nuclei coexist within the same cell before fusion.

What are fungi?

Eukaryotic organisms that are absorptive heterotrophs, typically possessing cell walls made of chitin, and often growing as filamentous structures called hyphae.

What are lichens?

A mutualistic symbiotic organism composed of a fungus (usually an Ascomycete) and a photosynthetic partner (either a green alga or a cyanobacterium), known for colonizing extreme environments.

What is Saccharomyces\ cerevisiae?

A species of yeast (a single-celled Ascomycota) widely used in baking and brewing due to its ability to ferment sugars into alcohol and carbon dioxide.