Fungi

Zygomycota -

" zygote fungi" Sexual Reproduction: zygosporangia = resistent to heat/cold and site of karyogamy Asexual Reproduction: haploid spores

Lichens

"mutualism" between fungus (structure), Alga or cyanobacterium ( provides food)

Heterotrophy

"other food" meaning they cannot manufacture its own food and instead obtains its food and energy by taking in organic substances, usually plant or animals. Ex. Humans, Dogs, Cats, Birds, Fish, etc.

What are the three main types of lichens?

1. Crutose lichen 2. Foliose lichen 3. Fruticose lichen

Beneficial effects of fungi

1. Decomposition - nutrient and carbon recycling. 2. Biosynthetic factories. Can be used to produce drugs, antibiotics, alcohol, acids, food (e.g., fermented products, mushrooms). 3. Model organisms for biochemical and genetic studies.

What are the ecological impacts of fungi?

1. Ecosystems depend on fungi as decomposers and symbionts: decompose food, wood and even plastics! 2. Some fungi are pathogens 3. Many animals, including humans, eat fungi

Fungus-Plant Mutualisms

1. Mycorrhizae are enormously important in natural ecosystems and agriculture 2. Plants harbor harmless symbiotic endophytes, fungi that live inside leaves or other plant parts 3. Endophytes make toxins that deter herbivores and defend against pathogens 4. Most endophytes are ascomycetes

What are the characteristics of basidiomycota: club fungi?

1. Named after transient diploid stage: basidium 2. Characterised by dikaryotic mycelium that reproduces sexually via basidiocarps 3. Important decomposers of wood / plant material Examples-Mycorrhiza-forming mutualists Mushroom-forming fungi Plant parasites e.g. rusts and smuts

Fungus-Animal Symbiosis

1. Some fungi share their digestive services with animals 2. These fungi help break down plant material in the guts of cows and other grazing mammals 3. Many species of ants use the digestive power of fungi by raising them in "farms"

Body form of fungi

1. Unicellular 2. filamentous (tube-like strand like hypha and hyphae) 3. Mycelium 4. Sclerotium 5. Multicellular like mycelial cords, rhizomorphs, and fruit bodies like mushroom

Yeasts

1. Unicellular: reproduce 2. Asexually by budding 3. Sexually by producing asci or basidia

Harmful effects of fungi

1. destruction of food, lumber, paper and cloth 2. animal and human diseases, including allergies 3. toxins produced by poisonous mushrooms and within food 4. plant diseases

Life cycle of zygomycete

1. gametangia begin to form hyphae of different mating types (+ or -) 2. the gamentangia then fuse to form heterokaryoticstate 3. heterokaryotic zygosporangium then develops 4. the zygosporangium develops rough and thickened cell wall-protect against harsh conditions until favorable to continue 5. when favorable the nuclei fuse and a diploid is briefly formed 6. meiosis follows and millions of haploid are formed by mitosis 7. the zygosporangium germinates and release the spores and the cycle begins again

mold

A rapidly growing fungus that reproduces asexually by producing spores. Some molds go through "fake sex" process

What allows fungi as decomposers and symbionts?

Absorption of nutrients

what is the purpose of spores ?

Allows fungus to more food source. Resistant state allows fungus to survive in periods of adversity and means of introducing new genetic combinations into a population

Life cycle of an ascomycete

Asexual : spores germinate > formation of kinetochore > mitosis undergoes > release of spores Sexual :only if there is an environmental cue mycelia > opposite mating types > form specialized cells (antheridia [male] ascogonium [female] > fusion > plasmogamy > forming the ascocarp (fusion of dikaryotic hyphae) > due to some environmental signal, karyogamy occurs > diploid nucleus > the diploid nucleus undergoes meiosis > before the spores are released thru mitosis, there is a doubling of spores

Life Cycle if Zygomycete

Begins with mycelia, mating types (+,-) > secret pheromones > undergo plasmogamy > upon plasmogamy is the development of zygosporangium > in this site karyogamy occurs > undergoes meiosis > sporangium forms > releases spores

Zygomycetes

Considered simple too do not have a septated cross wall - plasmogamy( first step to mating, fusing of the cytoplasm and has 2 nuclei ) formation of a specialized zygosporangium meiosis will occur here

Fungi

Eukaryotes, nearly multicellular(yeast is unicellular)

Hetrotrophic Absorbers

Fungi get carbon from organic sources. Hyphal tips release enzymes. Enzymatic breakdown of substrate. Products diffuse back to hyphae. Fungus is often hidden from view, it grows through its food through its food source (substratum)

Mycelia

Fungi grow as saprobes or parasites on variety of substrates. Also used in foods (Blue cheese ) and industrial production of drugs.

Pheromones

Fungi use sexual signaling molecules to communicate their mating type

Characteristic of Fungi

Have a cell wall present that is composed of cellulose and/or chitin. Eukaryotes have a true nucleus and other organelles present. No obligate anaerobes ( need oxygen to oxidize substrates to obtain energy). Fungi grow in almost every habitat imaginable ( spores) as long there is some type of organic matter present

Coenytic

Lack septa cross walls Grows rapidly Decomposers, pathogens, and some form mycorrhizal associations with plants

What are lichens good at detecting?

Lichens are nature's biological monitors of pollution and air quality

what happens during mutualism between the fungus?

Nutrients and water uptake for the plants and the plants give off carbohydrates for fungus and this is extremely important ecological role for fungi

How are fungi distinguished by other kingdoms?

Nutrition, Structural Organization, Growth, Reproduction

Pathogens

Parasites that cause disease

Hypha (hyphae)

Pha = singular , Phae = plural

What is hyphae septate of fungi?

They are divided into cells by cross walls called septa

What is the division of chytridiomycota ?

They are originally placed in the kingdom of Protista, they share many characteristics with fungi like .. Absorptive Nutrition, Chitin cell walls, Hyphae, Enzymes/metabolism. The earliest fungi evolved from protist and retained in flagella.

why does fungi reproduce by the use of releasing spores ?

They are unicellular, haploid, come from various shapes and sizes, in-favorable condition fungi produce enormous numbers of spores asexually, many fungi sexually reproduce only occurs in chance that can result in greater genetic diversity(carried by wind/water) and germinate in moist places with appropriate substrata( algae lives on rock for the animal that lives on top of it )

hetrokaryon

a haploid nuclei from each parent don't fuse right away, they coexist in the mycelium

mutalistic fungi

absorb nutrients from a host, but reciprocate to benefit the host

parasitic fungi

absorb nutrients from the cells of living hosts, some are pathogenic

mycelium

aggregate of hyphae

fruticose lichen

are even more finely branched and may hang down like beards from branches or grow up from the ground like tiny-shrubs

Mycorrhiza

are mutually beneficial relationships between the fungi and plant roots

Asexual reproduction less common than in...

ascomycetes

What are spores?

asexual (product of mitosis ) or sexual (product of meiosis) in origin

where are spores formed ?

directly on hyphae, inside sporangia, fruiting bodies

abuscular mycorrhizal fungi

extend hyphae through the cell walls of root cells and into tubes formed by invagination (inward movement) of the root cell membrane

Saprophyte or Saprobe

feed on dead tissues or organic waste (decomposers)

Parasites

feeding on living tissue of a host

Chytrids

flagellated spores, simple, don't have a septated cell wall

Crutose Lichen

form flat crusty plates

Ectomycorrhizal

form sheaths of hyphae over the surface of a root and typically grow into the extracellular spaces of the root cortex

Resulting dikaryotic mycelium grows...

forming mycorrhiza or mushrooms (basidiocarps)

The Move to Land for Fungi

fungi earliest colonizers of land probably formed mutualistic relationships with land plants, molecular analysis helped clarify evolutionary relationships among fungal groups , although areas of uncertainty remains

What is hyphae of aseptate of fungi?

fungi lack cross walls (coenocytic )

dikaryotic

haploid nuclei pair off two to a cell; such as a mycelium

Sclerotium

hardened mass of mycelium that generally serves as an overwintering stage

What is a haustoria ?

its a parasitic fungi that have been modified hyphae and penetrate the host tissue but remain outside the cell membrane

Mushroom cap supports and protects gills called

karyogamy; in the terminal, dikaryotic cells lining the gills produces diploid basidia

foliose lichen

leaf-like appearance, although lobed or branched structures are not true leaves

Saccharomyes cerevisiae

most important domesticated fungus like baking and brewing and model organism

Glomeromycota

mutualistic relationship with plant cells and mostly composed of roots

Symbionts

mutually beneficial relationship between a fungus and another organism

multicellular fungi

mycelial cords, rhizomorphs, and fruit bodies like mushroom

condia

not formed inside sporangia ; they are produced asexually at the tips of hyphae called condiophores - fungal component of lichens are usually an ascomycetes and fungi growing in nature can be yeast

Deuteromycetes

rapidly producing fungus with no sexual stages, may develop into a asexual fungus, producing zygosporangia, ascocarps, or basidocarps.

Ascomycota

sac fungi - Sexual Reproduction : asci ( sing = ascus ) - Asexual Reproduction: enormous numbers of asexual spores called condia

what decomposes complex molecules into simpler ones that can be absorbed ?

secrete hydrolytic enzymes and acids

Haploid basidiospores grow into...

short-lived haploid mycelia: under certain conditions, plasmogamy occurs

sexual reproduction in fungi

spores > germinate > formation of mycelium > plasmogamy > dikaryotic stage (cell that has 2 separate nuclei, the nuclei have not fused yet, dikaryon when the nuclei fuse, this is karyogamy)> karyogamy (fused nuclei diploid) > undergo meiosis > form haploid spores > repeat

asexual reproduction in fungi

spores > germination of spores > formation of mycelium > spore producing structures formed > repeat

Ascomycota

spores are produced in sags, inside the ascus they undergo meiosis & form spores ,before the spores are released, it doubles in # so each ascus releases 8 spores

Haphae Growth

the haphae grow from the tip, the mycelium is the extensive feeding web of the hyphae and the mycelia are the ecological active bodies of the fungi

Basidiomycota

they do not undergo meiosis before releasing spores and elaborate fruiting body (basidiocarp) containing many basidia that produce sexual spores (basidiospores)

How do fungi reproduce?

they release spores that are either reproduce asexually or sexually, output of spores from one reproductive structure is enormous in number reaching trillions, dispersed wildly by wind/water and spores germinate to reproduce mycelia if they land in moist areas where there is food.

Resulting basidium immediately...

undergoes meiosis producing four haploid basidiospores

Deuteromycota (imperfect fungi)

unicellular, reproduce asexually through budding, sexually by producing asci basidia