chapter 31 notes fungi. concept 31.1 all fungi are eukaryotic; most are multicellular mycete = fungi...
TRANSCRIPT
Chapter 31 Notes
Fungi
Concept 31.1
All fungi are eukaryotic; most are multicellular
mycete = fungiFungi differ from plants in nutritional
mode, structural organization, growth, and reproduction
Concept 31.1
Fungi are heterotrophs that acquire their nutrients by absorption- fungi digest their food outside their body by secreting powerful hydrolytic enzymes (exoenzymes) into the food.- decomposers, parasites, and mutualistic symbionts
Concept 31.1
Fungi have a large surface area and grow rapidly to assist with absorption
The bodies of fungi are constructed of tiny filaments called hyphae- the hyphae are divided into cells by cross-walls, or septa- cells walls are made of chitin
Concept 31.2
Fungi disperse and reproduce by releasing spores that are produced sexually and asexually- heterokaryotic stage: fusion of two hyphae that have genetically different nuclei
More than 100,000 fungi species are known; estimated that 1.5 million may exist
Phylum Chytridiomycota:- chytrids are mainly aquatic- saprobes or parasites- most primitive fungi; ancestors of protists
Phylum Zygomycota:- mostly terrestrial; live in soil or on decaying plants and animals- many form mycorrhizae, a mutualistic association with the roots of plants
Phylum Ascomycota:- sac fungi- range from unicellular yeasts to cup fungi- produce spores in saclike asci
Phylum Basidiomycota:- “club fungus”- mushrooms, puffballs, and rusts- important decomposers of wood and other plants
Concept 31.5
Molds, yeasts, lichens, and mycorrhizae have specialized lifestyles
Molds- a rapidly growing, asexually reproducing fungus
Yeasts- unicellular fungi that inhabit liquid or moist habitats
Concept 31.5
Lichens- symbiotic relationship of millions of photosynthetic microorganisms (alga) held in a mesh of fungal hyphae- the alga provides the fungus with food. The fungus provides a suitable environment for growth
Concept 31.5
Mycorrhizae- mutualistic association of plant roots and fungi- responsible for making nutrients able to be absorbed