Fungus Chapter 31

What characteristics are unique to Fungi?

Fungi are eukaryotic organisms, have cell walls made of chitin, absorb nutrients through external digestion, and reproduce by producing spores.

Why were Fungi thought to be closely related to plants? What do we now know about the relationship of Fungi to Plants and Animals?

Fungi were thought to be closely related to plants due to their stationary nature and growth in soil; however, they are now understood to be closer to animals genetically.

Define yeasts.

Yeasts are unicellular fungi that can ferment sugars.

Define hyphae.

Hyphae are long, thread-like structures that make up the body of a fungus.

Define chitin.

Chitin is a structural polysaccharide that makes up the cell walls of fungi.

Define mycelium.

Mycelium is the network of hyphae that forms the main vegetative part of a fungus.

Define septa.

Septa are cross-walls that divide hyphae into compartments.

Define coenocytic.

Coenocytic refers to hyphae that do not have septa, resulting in one large cell with multiple nuclei.

Define haustoria.

Haustoria are specialized hyphae that penetrate the tissues of a host organism.

Define ectomycorrhizal fungi.

Ectomycorrhizal fungi form symbiotic relationships with plant roots, surrounding but not penetrating the root cells.

Define arbuscular mycorrhizal fungi.

Arbuscular mycorrhizal fungi penetrate the root cells of plants and form arbuscules for nutrient exchange.

Define plasmogamy.

Plasmogamy is the fusion of cytoplasm from two parent fungal cells.

Define karyogamy.

Karyogamy is the fusion of nuclei from two parent fungal cells.

Define heterokaryotic/dikaryotic.

Heterokaryotic (or dikaryotic) fungi have two genetically distinct nuclei in a single cell or hypha.

Briefly describe the fungal life cycle. What are the unique features?

The fungal life cycle typically includes asexual and sexual reproduction through spores, with distinct phases of plasmogamy and karyogamy as unique features.

Why are fungi very large organisms but rarely seen?

Fungi can be large due to their extensive mycelium networks, which are often underground or hidden.

What mode of nutrition is shared among ALL fungi?

All fungi share absorptive nutrition, where they absorb nutrients from their environment.

Contrast absorptive vs ingestive feeding. Which do fungi do?

Absorptive feeding involves external digestion and nutrient absorption, while ingestive feeding involves internal consumption; fungi predominantly use absorptive feeding.

How do structure and function in fungi relate to their role in ecosystems?

Fungal structures such as hyphae maximize surface area for nutrient absorption, allowing them to play vital roles as decomposers and mutualists in ecosystems.

What is enzyme induction and what role does it play in fungal digestion and absorption?

Enzyme induction is the process where fungi produce specific enzymes to break down complex substrates, facilitating digestion and nutrient absorption.

What are some distinguishing features of Chytridiomycota?

Chytridiomycota have flagellated spores and are often aquatic or found in moist environments.

What are some distinguishing features of Mucoromycota?

Mucoromycota are known for their fast growth and often have coenocytic hyphae.

What are some distinguishing features of Ascomycota?

Ascomycota are characterized by the production of ascospores in sac-like structures called asci.

What are some distinguishing features of Basidiomycota?

Basidiomycota produce basidiospores on club-shaped structures called basidia.

What roles do fungi play as decomposers?

Fungi decompose organic matter, returning nutrients to the soil and recycling materials in ecosystems.

What are fungi as mutualists?

Fungi form mutualistic relationships with plants (mycorrhizae) and other organisms, enhancing nutrient uptake.

What are fungi as pathogens?

Some fungi cause diseases in plants, animals, and humans, impacting health and ecosystems.

Explain fungal farming.

Fungal farming is the mutualistic relationship where certain ants cultivate fungi as their food source.

What are fungi as endophytes?

Endophytic fungi live inside plant tissues without causing harm, often providing benefits to their host.

What are lichens?

Lichens are symbiotic associations between fungi and photosynthetic organisms, like algae or cyanobacteria.

Describe both types of mycorrhizae.

Ectomycorrhizal fungi surround roots, while arbuscular mycorrhizal fungi penetrate root cells, both enhancing nutrient exchange.

How to educate your neighbor about fungal morphology?

Describe the basic morphology as consisting of hyphae forming mycelium and fruiting bodies, illustrating growth and structure.

How do fungi feed and what ways is their morphology adapted?

Fungi feed by secreting enzymes and absorbing nutrients; their extensive hyphal networks increase efficiency.

How do fungi reproduce?

Fungi reproduce via spores through both asexual and sexual methods, highlighting their adaptability.