Chapter 29 Fungi Flashcards
All fungi are ___ and ___
All fungi are eukaryotes and heterotrophic
Fungi infiltrate and secrete ___ enzymes onto food and digest it outside the body, then ___ the predigested food into the body
Fungi infiltrate and secrete digestive enzymes onto food and digest it outside the body, then absorb the predigested food into the body
Fungal cells are enclosed by ___ ___ during at least some stage in their life cycle
Cell walls
In most fungi, the cell wall consists of ___ ___ including ___
complex carbohydrates including chitin
Most fungi are ___ except ___
most fungi are multicellular except yeast
hypha
branching gilaments that make up the mycelium of a fungus
body for of a fungus
multicellular
consists of hyphae that form a mycelium
molds
fungi that form mycelia
in most fungi, ___ are divided into individual cells containing one or more ___
in most fungi, hyphae are divided into individual cells containing one or more nuclei
Septa of many fungi have a ___ large enough to permit ___ to flow from cell to cell
Pore
organelles
most fungi reproduce by means of ___, ___ ___
microscopic, nonmotile spores
Spores are dispersed by
wind, water or animals
Spores are produced ___ or ___
asexually (yeast) or sexually
sexually produced spore
produced on specialized aerial hyphae or in fruiting structures
sporangia
structures in which spores are produced
the aerial hyphae of some fungi produce spores in large, complex reproductive structures called
fruiting bodies
the familiar part of a mushroom is a large
fruiting body
Yeasts repoduce by
Budding
budding
spores produced by mitosis and then released
Most fungi reproduce ___ and contain ___ nuclei
Most fungi reproduce sexually and contain haploid nuclei
monokaryotic
hyphae that contain only one nucleus per cell
dikaryotic
Hyphae that contain two genetically distinct nuclei within each cell
Presence of a dikaryotic stage is a defining character of phyla ___ and ___
ascomycetes and basidiomycetes
fungi are more closely related to ___ than to plants
animals
like animals, fungi have platelike ___ in their mitochondria
cristae
Genetic and structural similarities support grouping fungi with ___ and animals in the ___ clade
Genetic and structural similarities support grouping fungi with choanoflagellates and animals in the opisthokont clade
Five main groups of fungi
- Chytidiomycota
- Zygotmycota
- Glomeromycota
- Ascomycota
- Basidiomycota
about 95% of named fungi belong to phyla
ascomycota and basidiomycota
chytridiomycetes
- Only fungi with flagellate cells
- unicellular or have a simple body composed of a few cell which may have rhizoids that absorb food
- most are decomposers (such as parasites)
- A parasitic chytrid is partly responsible for declining amphibian populations
Zygomycetes
- not a monophyletic group
- most are decomposers
- some form symbiotic mycorrhizae
- a few cause disease in plants and animals
Microsporidia
small unicellular parasites that infect eukaryotic cells
decelopmental stages of microsporidia inside their host
- feeding stage
2. Repoductive stage
Spores of the microsporidia
each spore has a long, threadlike polar tube used to inject the contents of the spore into the host cell
microsporidia may be th
smallest and simplest eukaryotes
Microsporidia lack
mitochoondria, flagella, and golgi complexes
microsporidia ribosomes resemble
those of prokaryotes
microsporidia genomes
smaller than bacterial genomes
Glomeromycetes
- Have coenocytic hyphae
- reproduce asexually with large, multinucleate blastospores
- Endomycorrhizal fungi
endomycorrhizal fungi
symbionts that form mycorrhizae with the roots of most trees and herbaceous plants
arbuscular mycorrhizae
most widespread endomycorrhizae
hyphae inside the root cells form tree-shaped structures (arbuscules)
roots supply the fungus with
organic nutrients
fungus provides the plant with
nutrient minerals
growth of plant in phosphate-deficient soil is enhanced by a
fungal partner
some fungi also release ___ that protect plants from herbivores and pathogens
alkaloids
Ascomycetes
- most yeasts, powdery mildews, blue-green, pink and brown molds, decomposer cup fungi, and edible morels and truffels
- used to flavor cheeses, bake break, ferment alcohol, and as foods
- scientists use ascomycetes to produce antibiotics and as model organisms for cellular processes
Many ascomycetes form
mycorrhizae with tree roots, or join with green algae or cyanobacteria to form lichens
ascomycetes are the cause of
most fungal diseases of plants and animals including humans
ascomycetes are called
sac fungi because their sexual spores are produced in microscopic sacs called asci
Reproduction of yeasts
asexual reproduction is mainly by budding
reproduction sexually by forming ascospores
sexual reproduction of yeast
two haploid yeasts form a diploid zygote, which undergoes meiosis, resulting in haploid nuclei incorporated into ascospores
Basidiomycetes
- mushrooms, bracket fungi, and puffballs
2. many are decomposers, some form mycorrhizae, others infect important crops, a few cause human disease
basidiomycetes are also called
club fungi because of their microscopic club-shaped basidia, which are comparable in function to the asci of ascomycetes
Ecological importance of fungi
- Digest cellulose and lignin
- decompose animal carcasses, feces, branches, logs, and leaves
- Recycle, water, carbon, and minerals
Cattle digest cellulose and lignin with
gut fungi
ants disperse
fungi
fungi digest ___for ants
leaves
mycorrhizal fungi decompose ___ material; increase ___ ___ of roots
mycorrhizal fungi decompose organic material; increase surface area of roots
Cells of fungi and plant roots communicate
- signaling molecules stimulate fungal cells to shift to a presymbiotic growth phase
- A signaling pathway activates gene expression in the root cells
Glomeromycetes form ___ connections
endomycorrhizal
ascomycetes and basidiomycetes form
ectomycorrhizal connections
Lichen
a combination of a fungus and a photoautotroph
Typically, fungus forms most of lichen ___
thallus
The photoautotroph produces ___ carbon compounds for the fungus, but unclear how the photoautotroph benefits
The photoautotroph produces energy-rich carbon compounds for the fungus, but unclear how the photoautotroph benefits
Lichens secrete
acid that etches rock, releasing minerals
3 types of lichens
- Crustose
- Foliose
- Fruticose
Crustose
lichens are flat and grow tightly against a surface
Foliose
lichens have leaflike lobes
Fruticose
lichens grow erect and have many branches
