fungi Flashcards
Fungi traits
- chemoheterotrophic
- sessile
- common ancestor = unicellular flagellated protist
- can be yeast or moulds
Fungi phyla
- Chytrids
- Zygomycetes
- Glomeromycetes (endomycorrhiza, fungi)
- Ascomycetes (sac fungi)
- Basidiomycetes
Fungi as Yeasts
- unicellular but can form colonies
- reproduce via binary fission - asexual
- reproduce sexually with spores
- anaerobic and perform fermentation
- prefer most environments
Fungi as Moulds
- multicellular
- reproduce sexually and asexually via spores (can depend on environment)
- prefer humid environments with organic material
- live indoors, in decaying organic matter, and soil
- produce fuzzy hyphae on surface of organic matter
Coenocytic Hyohae
aseptate and have continuous cytoplasm with thousands of nuclei
Septate Hyphae
contain cross-walls that only allow cytoplasm to pass via holes and separate nucleases
Mycelia
- filamentous structure of many hyphae that increase surface area for enzyme secretion and absorption
- grow in length not width
Fungi Reproduction of Spores
- produce haploid spores sexually or asexually, and produce hyphae
- spores produce via mitosis AND meiosis, unlike plants (just meiosis)
- spores are resistant to desiccation
- spores represent dispersal
Fungi Parasitic Relationships
Plant:
- 2nd most important plant pest
- cankers and scabs are necroses caused by fungi digestion of living plant tissue
- cause wilt when hyphae block xylem and leave powdery mildews
Invertebrates:
- attack insects and atachnids
- slow death
- produce spires inside host and when fruiting starts, bursts through host body
Vertebrates:
- Cutaneous - infection occurs on outer layer of the skin due to fungi digesting dead skin and keratin
- hyphae grow in ring-shaped pattern
- localized subcutaneous - infection due to wounds
- systemic - infection widely spread inside host body
Fungi Decomposition
- break down large complex organic compounds into inorganic forms
- release C and N from dead tissues
- more important than bacteria when it comes to breaking down plant lignin
- speeds nitrogen cycle by releasing CO2 from dead organisms
Fungi Mutualism
- in cow guts
- farmed by leaf-cutter ants for colony in exchange for leaf mulch
- mycorrhizae
- ectomycorrhizae
- endomychorrhizae
- lichen
Mycorrhizae
- mycorrhizae: plant roots and fungi exchange carbohydrates from photosynthesis for access to water/minerals (almost all vascular plants have mycorrhizae associates)
Ectomycorrhizae
- ectomycorrhizae = on surface of root and provides water.minerals - Ascomycota, Basidiomycota, Zygomycota
Endomycorrhizae
- endomycorrhizae = hyphae penetrates cell root to provide defence against bacteria or herbivores - Glomeromycota
Lichen
- lichen: the symbiosis between hyphae mycobiont and photosynthetic partner (green algae or cyanobacteria) which receive C and N
- reproduction synchronized for soredia made by thallus (mycobiont around photobiont cell)
- fungus = host, provides place to grow, protection, retains water and minerals