Fungi

Mitosis

-Forms new hypha when spore germinates

Basidiomycota

"Club Fungi" -Produce sexual spores (basidiospore) on the outside of the basidium -Hyphae have septa

Mycorrhizae

"Fungus Roots" -Greek -Symbiotic associations between the hyphae of certain fungi and the roots of plants

Plasmogamy

(Sexual Reproduction) -Hyphae of two genetically compatible mating types come together, and their cytoplasm fuses, -The resulting cell has two haploid nuclei, one from each fungus, beginning the dikaryotic stage (n+n)

Karyogamy

(Sexual Reproduction) -When the two haploid nuclei fuse resulting in a cell containing a diploid (2n) nucleus known as a zygote nucleus.

Dikaryotic

(n+n) -Describes hyphae that contain two genetically distinct, sexually compatible nuclei within each cell.

Asci

(seen in lab) -Microscopic sacs that are the sexual spores produced by ascomycetes -form at the tips of some specialized hyphae known as conidiophores

Asexual Spores

- Can be produced by mitosis and are genetically similar -When these spores germinate they develop into hyphae

Coenocytic Hyphae

- Hyphae that form an elongated multinuclear cell (no septa) are coenocytic

Ascomycetes

-Affect humans more than any other group of fungi (good and bad) -Produce conidia, ascospores, and ascocarp (fruiting body lined with asci) -Can be both heterothallic and homothallic

Conidia

-An asexual spore that is usually formed at the tip of a specialized hypha called a conidiophore.

Economic Usefulness of Fungi

-As food (mushrooms, morels, truffles) -In production of beer, wine, and bread (yeasts) -Production of cheeses and soy sauce -Production of citric acid and other industrial chemicals

Chytridiomycota (Chytrids) Diploid Thallus

-Bears zoosporangia that produce sporangia in which haploid zoospores form new haploid thalli

Opisthokonts

-Clade within the supergroup Unikonts, includes the choanoflagellates, the animals, and the fungi -Key characters shared in this clade: 1.) Flagellate cells with single posterior flagellum that propels the cell 2.) Platelike cristae found in the mitochondria of animal and fungal cells.

Basidia

-Comparable to the asci of ascomycetes. -Produced on the outside of basidium -Develop on the surface of gills in mushrooms, a type of basidiocarp (fruiting body)

Monokaryotic

-Describes hyphae that contain only one nucleus per cell.

How are the cell walls of Fungi different than those of Plants?

-Fungal cell walls do not contain cellulose. Rather, they contain chitin, a polysaccharide found in insect skeletons.

Fungal Plant Disease

-Fungal hyphae infect plants through stomata -Haustoria (hyphae branches) penetrate plant cells and obtain nourishment from cytoplasm ex: wheat rust, dutch elm disease, chestnut blight

What are the distinguishing characteristics of kingdom Fungi?

-Fungi are Eukaryotic heterotrophs - Fungi secrete digestive enzymes onto food, then absorb predigested food -Cell walls with chitin*; highly resistant to decay. [*polymer, nitrogenous sugar units]

Usefulness of Fungi in Research

-Fungi are model organisms for molecular biology and genetics -Biological control of insects, such as mosquitos that transmit malaria

Glomeromycetes

-Have coenocytic hyphae -Reproduce asexually with large, multinucleate spores called blastospores. -Sexual reproduction has not been documented. -Glomeromycetes are symbionts that form intracellular associations with the roots of most trees and herbaceous plants.

Arbuscules

-Hyphae inside root cells that form branched, tree-shaped structures -Site for nutrient exchange between the plant and the fungus.

Soredia

-In lichens, a type of asexual reproductive structure that consists of a cluster of algal cells surrounded by fungal hyphae.

Ascocarp

-In sac fungi, the reproductive structure in which haploid nuclei fuse to form a zygote

Are fungi autotrophs or heterotrophs?

-Like animals, fungi are heterotrophs. -Fungi cannot produce their own organic materials from a simple carbon source (carbon dioxide).

Hyphae

-Long, branched, threadlike filaments cells of the fungi. -Most fungi have perforated septa that divide hyphae into individual cells -Growth occurs only at the tip of the hyphae

Lichen

-Looks like a single organism, but is actually a dual organism, a combination of a fungus and a photoautotroph. - 3 main growth forms: crustose, foliose, fruticose

Heterothallic

-Meaning that an individual fungal hypha mates only with a hypha of a different mating type. (+) and (−)

Chytridiomycota (Chytrids)

-Most are unicellular or composed of a few cells that form a simple body (thallus) -*Gametes and zoospores are flagellate -Has a haploid and diploid thallus in different parts of life ex: Allomyces

Decomposers (Fungi)

-Most fungi are decomposers that break down organic compounds (dead organisms, leaves, garbage, and. wastes) into simpler nutrients (H2O, CO2) that can be recycled

Fungi structure

-Most fungi are multicellular with hyphae, mycelium, and grow apically -Fungi can be unicellular (yeasts)

Fungi Pathogens

-Opportunistic pathogens in humans ex: Ringworm, athlete's foot, candidiasis, histoplasmosis

Fungi in Medicine

-Penicillin and other antibiotics

Meiosis

-Produces 4 haploid (n) nuclei -Each nucleus develops into a spore

Chytridiomycota (Chytrids) Haploid Thallus

-Produces two types of flagellate gametes that fuse -Both plasmogamy and karyogamy occur, producing a flagellate zygote

Microsporidia

-Small, unicellular parasites that infect eukaryotic cells, particularly those with compromised immune systems (HIV) -Classified with the zygomycetes (for now)

Fungi Toxins

-Some fungi produce mycotoxins such as aflatoxins that cause liver damage and cancer.

Spores (fungi)

-Spores, reproductive cells that can develop into new organisms. -Produced on aerial hyphae, land in a suitable spot and germinate -Produced in the sporangia

Fruiting Bodies

-The large, complex reproductive structures, made of the aerial hyphae of some fungi, that produce spores ex: The familiar part of a mushroom

What monophyletic "supergroup," contains amoebozoa, fungi, animals, and a few protists, including the choanoflagellates?

-Unikonts.

Mycelium

-What the hyphae of fungi grow into forming a tangled mass or tissue-like network

Asexual Reproduction

-Yeasts reproduce asexually, primarily by forming buds that pinch off from the parent cell -Multicellular fungi can also reproduce asexually. Spores are produced by mitosis and then released into the air or water.

Homothallic

-which means self-fertile having the ability to mate with themselves.

In which fungi are hyphae coenocytic?

-zygomycetes and glomeromycetes hyphae are coenocytic

Do fungi reproduce asexually or sexually?

Both! MOST fungi reproduce both sexually and asexually!

Generic Life Cycle of Fungi

Notice the arrangement of stages and processes

Zygomycetes

ex: Rhizopus stolonifer (Black bread mold) and Pilobolus -Not a monophyletic group -Many are decomposers that live in the soil -Some species have symbiotic association with plants and animals -Sexual reproduction is heterothallic

Endomycorrhizal Fungi.

fungi that extend their hyphae through the root cell wall and into tubes formed by invagination of the root cell membrane