Ch 22 the Diversity of Fungi

Lichen

-a results of a symbiotic relationship between fungi and single-celled green algae (or cyanobacteria). -algae provide nutrients from photosynthesis, fungi provide protection. the fungus often consumes the lion's share of the photosynthetic product, leading some researchers to conclude that the symbiotic relationship in lichen is more one sided

How do fungi affect humans?

-attack plants that are important to humans ( crop disease, dutch elms disease) - can cause human disease (athletes foot, jock itch, ringworm, yeast infections -fungi can produce toxins (certain molds are highly toxic, -many antibiotics are derived from fungi (penicillin, -yeasts (single celled ascomycetes), wine and beer.

plant cells vs fungal cells

-both are surrounded by cells walls -only fungal cells contain chitin (a substance that strengthens cell walls found in the exoskeleton of insects and crabs.

glomeromycetes

-live in intimate contact with roots of plants -hyphae of glomermycetes penetrate the cells of roots and this invasion does not harm plants. This beneficial relationship is called mycorrhiza.

Chytrids

-most live in fresh water -spores have a single flaggellum on one end -feed on dead aquatic plants

asexual reproduction

-mycelia and spores of fungi are haploid. -a haploid mycelium produces haploid asexual spores by mitosis -if an asexual spore is deposited in a favorable location, it will begin mitotic divisions and develop into a new mycelium -this simple reproductive cycle results in the rapid production of genetically identical clones of the original mycelium

All six main groups of fungi are

Chytrids -rumen fungi -blastoclades -glomeromycetes -basidiomycetes -asomycetes

Can Fungi move?

No, they compensate however with hypae that can grow rapidly in any direction within a suitable environment. -periodically, the hypae will differentiate into reproductive structures that project above the surface beneath which mycelium grows.

Mycelium

an interwoven mass of one-cell thick, threadlike filaments called hyphaee (singular hypha),

Rumen fungi

anaerobic (do not require oxygen) -reside mainly in the digestive tracts of plant eating animals like cows, sheep, elephants. -these animals are not able to digest cellulose (a major component of plant tissue) and rely on this symbiotic relationship with rumen fungi in their guts

List some fungi that attack crops. to which taxonomic group do they belong?

basidiomycete plants pests called rusts and smuts attack grain crops. U99, an especially virulent strain of a wheat disease called black stem rust, is currently a major threat to the worlds wheat.

Sexual reproduction

begins when a filament haploid hypae of different, compatible, mating types fuse, resulting in cells that contain nuclei from both parents. -these nuclei subsequently fuse, generating a diploid zygote that undergoes meiosis to yield haploid spores.

describe the structure of the fungal body. How do fungal cells differ from most plant and animal cells?

body is a mycelium--an interwoven mass of threadlike filaments called hyphae. Fungal cells differ from plant cells in that they do not have chloroplasts and cannot carry out photosynthesis to make their own food. ... Like plants, fungi have a cell wall but it is composed of chitin, fungi have a cell wall, animals dont. both are heterotrophs.

Do fungi produce sexually or asexually?

both. -for the most part, fungi reproduce asexually under stable conditions and sexually under conditions of environmental change or stress.

Basidiomycetes

called club fungi bc they produce club-shaped reproductive structures. -members typically produce sexually. -fruiting bodies are mushrooms, puffballs, shelf fungi, and stinkhorns. -the undersides of mushrooms are leaflike gills on which basidia are produced. -basidiospores are released by the billions through openings in the tops of puffballs or from the gills of mushrooms and are dispersed by wind and water.

which 3 types of fungi produce swimming spores?

chytrids, blastoclades, and Rumen fungi

What is another name for basidiomycetes?

club Fungi

blastoclades

have a clade or "nuclear cap" that is found near the nucleus of blastocade s pores. -live in freshwater or soil. -some a parasites of water fleas or mosquito larvae.

myocorrhizae

important symbiotic associations between fungi and plant roots. -mycorrhizal fungi surround the plant root and invade the root cells. fungi receive energy rich sugar molecules that are produced photosynthetically by plants. -fungi absorb nutrients from the soil, passed some of them directly unto root cells. phosphorous and nitrogen are among these nutrients passed from fungi to plant.

symbiotic relationship

intimate,long term relationships. not necessarily mutually beneficial. often times the fungi harms the host

__________________are symbiotic associations of fungi and green algae. _____________________________are symbiotic, mutually beneficial associations of fungi and plant roots. Some fungi are ______________________ that live inside the above ground tissues of plants

lichin myocorrhizae endophytes

in fungi, asexual spores are produced by__________________and have ________________-set(s) of chromosomes. Sexual spores are produced by ______________________cell division in a(n) ______________________ and have ___________________set(s) of chromosomes.

mitotic cell division one (haploid) meiotic cell division zygote 2 (diploid)

fairy ring

mushrooms emerge in a fair ring from an underground fungal mycelium, growing outward from a central point where a single spore germinated, perhaps centuries ago.

examples of fungal reproductive structures

mushrooms, puffballs, powdery mold we see on spoiled food. -represent only a fraction of the complete fungal body

the fungal body is an ___________________, and is composed of microscopic threads called ________________ that may be subdivided into many cells by _________________________. the cell walls of fungi are strengthened by _________________________.

mycelium hyphae septa chitin

hyphae

one-cell thick threadlike filaments that form mycelium.

ascomycetes

reproduce both sexually and asexually. -some live in decaying forest vegetation and form either beautiful cup-shaped reproductive structures or corrugated, mushroom-like fruiting bodies called morels -also include many of the colorful molds that attack stored food and destroy fruit and grain crops -contain the species that produces penicillin, the first antibiotic -yeasts, some of the few unicellular fungi, are also ascomycetes

black bread mold

reproduces both sexually and asexually.

the portions of a fungus that are visible to the naked eye are often structures specialized for _________________________. These structures release tiny __________________, which are dispersed to produce new fungi

reproduction; spores

what is another name for ascomycetes

sac fungi

septa

some hyphae are subdivided--by partitions called septa--into many cells, each containing one or more nuclei. Pores in the septa allow cytoplasm to stream between cells, distributing nutrients.

describe how fairy rings of mushrooms is produced. why is the diameter related to its age?

spores give rise to hyphae that grow outward from the original spore in a roughly circular pattern as the older hyphae in the center die. -the subterranean body periodically sends up mushrooms, which emerge in the ring like pattern -the further the ring, the older the mushroom.

how are fungi decomposers

they consume dead tissue from animals and plants and give those by products of decomposition back the the earth.

How do fungi obtain their nutrients?

through other organisms. -fungi survive by breaking down nutrients stores in the bodies or wastes of other organisms. -some fungi digest bodies of dead organisms. -others are parasitic and can cause disease on their hosts. -unlike animals, fungi do not ingest food. they secrete enzymes that digest complex molecules outside their bodies, breaking down the molecules into sub units that can be absorbed.

morels

type of asomycete that is a mushroom fruiting body.

Spores

what fungi develop from -haploid, contain only a single copy of each chromosome. -fungal spores are tiny and extraordinarily mobile. -cells that give rise to a new individual