Ch29: The fungi

Mycologists estimate there may be as many as _______ species of fungi

1.5 million

• Like prokaryotes, most fungi ________ organic matter and recycle the elements into the environment

• many form vital ________ _____________

• some live symbiotically with algae and cyanobacterial as ______

• some are _________ and _________ that cause disease in animals or plants

• decompose

• symbiotic associations

• lichens

• parasites & pathogens

All fungi are __________ and ___________

• fungi infiltrate and secrete digestive enzymes onto food and _______ it outside the body, then ______ the predigested food into the body

eukaryotes & heterotrophic

• digest, absorb

• fungal cells are enclosed by ____ _____during at least some stage in their life cycle

• in most, the cell wall consists of complex ______________, including chitin

• cell walls

• carbohydrates

Most fungi are multicellular except ______

yeast

the body of a multicellular fungus consists of ______ that form a _________

hyphae, mycelium

fungi that form mycelia are called ______

molds

______ grow into and infiltrate food sources, and nutrients are absorbed through its very large surface area

hyphae

in most fungi, hyphae are divided septa into individual cells containing one or more _____

nuclei

septa of many fungi are perforated by a pore large enough to permit organelles to flow from ____ to ____

• coenicytic fungi lack _____

cell to cell

• septa

Most fungi reproduce by means of microscopic, nonmotile ______

• dispersed by ______, ______, or _________

• spores are produced _________ (yeasts), or _________ on specialized aerial hyphae or in fruiting structures

spores

• wind, water, animals

• asexually, sexually

Sporangia

structures in which spores are produced

the _______ _______of some fungi produce spores in large, complex reproductive structures (fruiting bodies)

aerial hyphae

Yeasts reproduce by _________

• multicellular fungi also reproduce ________

  -spores produced by ______ and then released

budding

• asexually

  -mitosis

Most reproduce _______ and contain ________ _______

• hyphae of two genetically compatible mating types come together and their ________ fuses, resulting in a cell with ___ haploid nuclei, which fuse, resulting in a cell containing a _______ nucleus

sexually, haploid nuclei

• cytoplasm, two

• diploid

Hyphae that contain only one nucleus per cell are ____________

monokaryotic (n)

Hyphae that contain two genetically distinct nuclei within each cell are ________

dikaryotic (n+n)

Systematists now view fungi as more closely related to ________ than ________

animals, plants

Like animals, fungi have platelike _______ in their mitochondria

cristae

Flagellate cells propel themselves with a single posterior _________

flagellum

Five main groups of fungi exist, but main two are:

ascomycota & basidiomycota

Only fungi with flagella

• are __________ or have a simple body composed of a few cells (thallus)

chytridiomycetes

• unicellular

some chytrids produce branched, coenocytic mycelia

• allomyces undergoes alternation of generations; part of life as a ______ ______ and part as a _______ _______

haploid thallus, diploid thallus

In chytrids, gametes secrete an attractant pheromone in order to…

• plasmogamy and karyogamy occur, resulting in a motile ________ _______

• zoosporangia produce flagellate diploid zoospores that develop into _______ _____; meiosis occurs in resting sporangia, producing ________ _________

attract animals that will rub against & spread spores

• diploid zygote

• diploid thalli, haploid zoospores