Quiz#5- Fungi Flashcards
What is a fungus? What are the key characteristics of the kingdom Fungi? What are the main body forms of fungi (e.g., multicellular vs. unicellular)?
key traits are absorptive heterotrophy(sectreting digestive enzymes to break down large food mole in the environment and presence of chitin in their cell walls.most fungi are multicellular however some are unicellular are found in each fungal group. The zygospore, club and sac fungi all contain the unicellular yeast.
mycelium
this is the body of the multicellular fungi, composed of microtubule filaments called hyphae
hyphae
are microtubule filaments in the multicellular fungi that have cell walls strengthened by chitin, a nitrogen containing polysaccaride..tthey extend great distances to take up nutrients
yeast
unicellular forms of fungi present in zygospores, club and sac fungi,
septa
incomplete cross-walls that divide the hyphae into cell-like compartments…they are incomplete because they have pores in them…those that contain these septa are called septate hyphae
many fungi are saprobes, what does this mean?
fungi that are saprobes, absorb nutrients form dead organic matter through their plasma membranes
Fruiting body
The mycelium organization into a reproductive body…this happens when a secual spore is produced…it is body of fungi…such as mushroom
parasitic fungi
absorb nutrients from theur living hosts,
mating types
the mating(sexula repro) bt some fungi may be within the same species as long as different mating type. INDIVIDUALS MAY DIFFERE GENETICALY BUT OFTEN VISUALLY AND BEHAVIORALLY THE SAME…so in sexual phase fungi is characterized by mating type (+,-) rather than male or female
pathogenic fungi
are a major cause of death on people with weak immune systems such as those with AIDS and they are a growing problem in human health internationally, Also they infect amphibian speceis around the world, and are the most importatn plant pathogens more so then bacteria and viruses.
symbiosis
relation where the two organisms live in constat interaction with each other…it can be a mutual parasitic or commensalism symbiosis
mutualism
form of symbiosis where bothe organisms benfeit from the interaction
lichens
are fungal associations with cyanobacteria, photosynthetic alga or both..this association is nt withing single roganisms but rather a meschowrk of different ones… so the fungus, photosynthitic microorganism, (unicellular alga or cyanobacteria) can include various kinds of each, thats why there are nearly 30, 000 soeceis of lichens……lichens are able to live in harsh environments but cannot handle air pollutatns and therefore are a key indicator of pollution levels. …they can be found as colored powder like, leafy, or shrubby appearance
mmychorehizae
are associations of fungi and plant roots, where the fungi gets its organic compunds from the plant and in turn provides the plant with nutrients that boost the plant growth.w/o this interaction many plants grow poorly
lichen symbiosis
the interaction/symbiosis of a lichen can be mutualistic with the algal cell b/c they relase photosynthetic products at a greater rate even when the fungi goes through its cell wall and presses against it…however symbiosis with the photosyntheitc cells decreases growth rate in comparison with their growth in fungi absence,..BUUT in some places these photosynthetic cells woulnt grow if it werent for the fungi.
mycorrhizae symbiosis
the symbiosis is based on 2 types depdneing on if the hyphae penetrate the plant cell wall or not. In one(eg ectomycorrhizae) type the hyphae wraps around the roots and doesnt penetrate the cell wall rather penetrates the soil and increases the toot surface area allowing more nutrients and water for vascular plants ….In another(eg stbuscular mycorrhizae). the hypahe penetrate the cell wall(not plasma mem) and forms tree like structures, ,,which then help with drought and temp resistance…it ahs been argues that the evolution of mycorrhizae was the single most imp step in colonization of terrestrial envir.
plasmogamy-in terrestrial fungi
fusing of two individuals hypahae cytoplams, which are of different mating type, which fuse even before their nuclei fuse
karyogamy
the fuse of two individual nuclei, from diff mating type hyphae
key features in in sac and club fungi….sexual reproduction..
happens in two steps plasmogamy(cytoplams fuse) and Karyogam,y(nuclie fuse)… where 2 gentically different haploid nucleir coexists and diviede within the same hypha—-dikayon…in this stage there are no gametes…only nuclei that fuse, so the only diploid stage is that of the zygote..however the ploidy of how the two cytoplasm have fused is called dikaryotic(n+n) so not haploid nor diplod…this stage lasts for months or even years in the club fungi but is short lived in the sac fungi
dikaryon—synapomorphy of club and sac fungi
this is a stage that is inclcuded in the sac and club fungi life cycles where a single hypha has two genetically distict nuclei, so this hypha is called heterokaryon
describe the generalized cycle of fungi
two diff mating types fuse in plasmogamy….then may have dikaryotic stage…fertilize so nuclei fuse and produce a 2n zygote…that will then undergo meiosis to create a spore-producing structure…that will give off the spores that undergo mitosis to begin an asexual reproduction where the different mating types divide and start the cycle again.
sac fungi(ascompycota
large diverse group of fungi found in marinem, freshwater, and terrestrial habitats. ..it has serptate hyphae..have ascus or asci reproductive sacs…and have a shortlived dikaryotic stage…sac fungi can be edible(morels, truffels), paristic in floering plants, prodiuction and brewing, antibiotic penicillin
ascus
are sexual reprosductive structures in the sac fungi.. containging sexually producing ascospores…the asci may be very diverse and characterize the sac fungi
ascoma
the specialized fruiting structure that may or may not contain the asci
