chapter 32 fungi

fungi

an abundant and diverse group of heterotrophic eukaryotic organisms, principally responsible for the decomposition of plant and animal tissue

hyphae

In fungi, a highly branched multicellular filament that provides a large surface area for absorbing nutrients.

mycelium

a network of branching hyphae

chitin

A modified polysaccharide containing nitrogen that makes up the cell walls of fungi and the hard exoskeletons of arthropods.

septa

in fungal hyphae, a wall that partially divides the cytoplasm into separate cells

yeasts

a single-celled fungus found in moist, nutrient-rich environments

ectomychorrihizae

One of the two main types of mycorrhizae; ectomycorrhizae produce a thick sheath of fungal cells (hyphae) that surround the root tip, as well as supply hyphae that grow between, but do not penetrate, cells in the interior of the root.

endomycorrhizae

One of the two main types of mycorrhizae; endomycorrhizal hyphae penetrate into root cells, where they produce highly branched structures (arbuscules) that provide a large surface area for nutrient exchange.

endophytes

a fungus that lives within leaves and that may help the host plant by producing chemicals that deter pathogens and herbivotes

lichens

stable association between a fungus and a photosynthetic microorganism, usually a gree alga, but sometimes a cyanobacterium

fruiting bodies

a multicellular structure in some fungi that faciliates the dispersal of sexually produced spores

plasmogamy

the cytoplasmic uion of 2 cells

karyogamy

fusion of 2 nuclei following plasmogamy

heterokaryotic

Describes a stage in the life cycle of some fungi, in which plasmogamy is not followed immediately by karyogamy and the cells have unfused haploid nuclei from both parents.

dikaryotic

having 2 haploid nuclei, one from each parent in each cell

mating types

Genetically distinct forms of individuals of a fungus species that, by enabling fertilization only between different types, prevent self-fertilization and promote outcrossing.

parasexual

describes asexual species that generate genetic divsersity by the crossing over of DNA during mitosis

chytrids

primarily aquatic fungi that have simple, often unicellular bodies and that produce flagellated gametes and spores

zygomycetes

A group of fungi that produce hyphae undivided by septa and do not form multicellular fruiting bodies; they make up less than 1% of known fungal diversity.

glomeromycetes

a group of fungi of low diversity but tremendous ecological importance that occurs in mycorrhizae

ascomycetes

a group of dikaryotic fungi where nuclear fusion and meiosis take place in an elongated saclike cell called as ascus; also called sac fungi

basidiomycetes

a group of dikaryotic fungi where nuclear fusion and meiosis take place in a slub-shaped cell called a basidium; also called club fungi