Biol 200B 1st Edition Lecture 22Outline of Current LectureI. FungiII. Fungal cellsa. Cell wall and extracellular digestion III. Fungal bodyIV. Reproductiona. Sexual and asexualV. Evolutionary HistoryCurrent LectureFungi- Eukaryotes – membrane bound organelles- All heterotrophs - More closely related to animals than plants- Important ecological roles:o Decomposerso Mutualistic symbionts with animals and plantso Diseases of animals and plants - Mushroom – “tip of the iceberg”, most biomass is below ground- Parasitic fungi infect corn and other crop plants- Saprophytic fungi rot fruits and vegetables - Important to vascular plants - Mycorrhizal fungi form extensive networks in soil and help plant growth- Important roles in nutrient cycles (some digest wood)Figure 32.7Fungal cells - No chloroplasts- (most) have mitochondria, do aerobic respiration like almost all eukaryotes - Rigid cell wall- Extracellular digestion – because rigid cell wall do not allow for big food- Cell walls of chitin, not celluloseo More resistant to microbial decayThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Insect exoskeletonsFugal body - Single celled fungi – “yeasts”- Multicellular have web like bodies – mycelia (mass of interwoven hyphae)o Filamentous o Lack specialized tissues, organs o But can be complex - Some can be both- Hyphae – filaments making up fungal body a) Septae hyphaeb) Coenocytic hyphae - Both reproductive structure and mycelium composed of hyphae - Specialized hyphae of fungus that captures/digests nematodes (adapted for trapping andkilling prey)Reproduction- Many reproduce asexually and sexually - Sexual lifecycles complex, different than plants and animals o Most don’t have “male” or “female” structures- Some only reproduce asexually Evolutionary History - Earliest fossils ~ 460 mya- Early vascular plant fossils suggest fungal symbionts ~ 420 mya Mysterious Microsporidians - All are intracellular parasites of animals - Have nucleus but lack mitochondria, golgi apparatus, peroxisomes - Are in fungi clade (says their DNA)- Have mitosomes – organelle derived from mitochondria; function not well understood Fungi and Land Plants; Figure 32.9Lichens: fungi/algae
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