The 2N megasporocyte nucleus undergoes meiosis to produce haploid nuclei.

1. Fig. 38.4 The 2N megasporocyte nucleus undergoes meiosis to produce haploid nuclei. One of these 1N nuclei divides multiple times by mitosis, producing several 1N clones. (The function of most of these cells is unknown.) Double fertilization produces a 2N zygote and 3N endosperm

2. Kingdom Fungi

3. Characteristics of Fungi • Briefly describe an example in each of the following fungal lifestyles: • decomposers • parasites • symbionts • Fungi are NOT plants • Absorptive heterotrophs • Reproduce by spores • reproductive bodies are often the most visible • “Ecologically active” • hyphae = tubular units of construction • secrete exoenzymes Justify this statement…

4. Fig 31.1 fruiting bodies both are composed of hyphae mycelium

5. ? (Protista) Fig 32.2 Proposed Phylogeny of Eukaryotes Fig 28.8

6. Fig 31.4 asci zygosporangia basidia Where do chytrids live? Classification in these three phyla is based on sexual reproductive structures motile spores

7. tubular hard wall of chitin around the cell membrane septa (perforated cross-walls) may form compartments (± cells) multinucleate Hyphae Septate hypha Coenocytic hypha Haustoria* *80% of plant diseases are caused by fungi What do you think is the purpose of perforated cross-walls?

8. Hyphal growth Where would you find the hyphae of most fungi? • Hyphae grow from their tips • Mycelium = extensive, feeding web of hyphae • Mycelia are the ecologically active bodies of fungi Why is SA important? This wall is rigid Only the tip wall is plastic and stretches

9. What does absorptive heterotrophic nutrition look like? • Fungi get their energy and raw materials from organic sources in their environment • The products of digestion diffuse back into hyphae Products Enzymatic breakdown Nucleus “hangs back” and directs metabolism Enzymes Products diffuses back into hyphae for use

10. Modifications of hyphae Fig 30.2 (don’t worry about the terms we don’t discuss in class)

11. Reproduction by spores What is the primary purpose of spores? Classification of fungi is based on which mode of spore production? • Spores are reproductive cells • Sexual • Asexual • Produced • fruiting bodies • inside sporangia • directly on hyphae Penicillium hyphae (Ascomycota) Pilobolus sporangia (Zygomycota) Amanita fruiting body (Basidomycota)

12. Fungal Ecology • Saprobes • Decomposers • Mostly of plants, some animals • Parasites • Harm host • Mostly on plants, some animals • Mutualists • Lichens • Mycorrhizas

13. Zygomycota – “zygote fungi” • Sexual - zygosporangia • Asexual spores - common • Hyphae have no cross walls • Grow rapidly Fig 31.6 Rhizopus on strawberries

14. Sexual zygsporangium with one zygospore Asexual sporangium with spores inside Fig. 31.7 Fig 31.7 Life cycle of Rhizopus You are not responsible for the details of this life cycle. Life cycle is predominantly haploid

15. Ascomycota – “sac fungi” • Sex. – asci • Asex. – common • Cup fungi, morels, truffles • Important plant parasites & saprobes • Yeast - Saccharomyces • Most lichens A cluster of asci with spores inside

16. Ascomycota – “sac fungi”

17. 1 cm Aleuria

18. Fig 31.9b Tuber melanosporum The black french truffle

19. Basidiomycota – “club fungi” • Sex – basidia • Asex – not so common • Long-lived mycelia • Rusts & smuts – primitive plant parasites • Mushrooms, puffballs • Enzymes decompose wood • Mycorrhizas SEM of basidia and spores See Fig. 31.12

20. Marasmius oreades - “Fairy Ring” From:http://botit.botany.wisc.edu/toms_fungi/mar2003.html

21. A rust growing on a currant leaf 0.5 cm

22. Amanita, “death angel” Inocybe, contains muscarine Boletus edulis Cantharellus, the chanterelle

23. Fomitopsis

24. Hyphal fusion of haploid mycelia mycelium and fruiting body are dikaryotic haploid mycelium Mushroom Life Cycle N 2N N+N Meiosis Nuclear fusion in basidium Fig 31.12 young basidia - the only diploid cells

25. “Alternative” fungal lifestyles • Yeasts • Molds • Mycorrhizas • Lichens

26. Yeasts • Single celled fungi • Adapted to liquids • Plant saps • Water films • Moist animal tissues Candida Saccharomyces

27. Molds • Rapidly growth • Asexual spores • Many of human importance • Food spoilage • Food products • Antibiotics, etc. Noble Rot - Botrytis Fig 31.21 Antibiotic activity

28. Mycorrhizas • “Fungus roots” • Mutualism between: • Fungus (nutrient & water uptake for plant) • Plant (carbohydrate for fungus) • Several kinds • Zygomycota – hyphae invade root cells • Ascomycota & Basidiomycota – hyphae invade root but don’t penetrate cells • Extremely important ecological role of fungi!

29. Lichens • “Mutualism” between • Fungus – structure • Alga or cyanobacterium – provides food • Form a thallus • Foliose • Fruticose • Crustose By what process do these symbionts produce food for the fungus? Fig 31.16

30. Lichen internal structure What do the fungi provide in this symbiotic relationship? Lobaria Fig 31.17

31. Lichens as biomonitors • Thalli act like sponges • Airborne dust, minerals, etc. adsorb to the lichen surface • Some species more sensitive • Which species are present can indicate air quality • Most resistant species can also be analyzed for pollutants

32. Lichen diversity These photos taken by Fred Rhoades Visit: Fred Rhoade's Lichen Page

33. Caloplaca & Verrucaria

34. Two species in the fruticose lichen of the genus, Cladonia

35. Peltigera

36. 1 cm Basidiomycote lichen, Omphalina