1. One large, multinucleated cell with no cell walls…
Next: What am I??
One large, multinucleated cell with no cell walls…

2. Revisiting the Protists??

3. Kingdom (?) Protista
60,000 known species of mostly unicellular eukaryotes
Other eukaryotes that are not Fungi, Plants or Animals also included

4. The “Protista Problem” It’s a paraphyletic taxon!!

5. Ecological Roles- Protista
Can divide the Protists into three categories:
1. Protozoa- Animal-like, injestive
2. Absorptive protists – fungus-like
3. Photosynthesitc protists- algae

6. The Absorptive Protists: A Closer Look

7. The Plasmodial Slime Mold Life Cycle

8. The Dictyostelida- Cellular Slime Molds
Feeding stage consists of solitary cells functioning individually
When food is low, cells follow chemical trails to form an aggregate (pseudoplasmodium)
Cells in the aggregate maintain their membranes
Haploid organisms!
Most have no flagellated stages

9. Dictyostelid Cinema (Cellular Slime Molds)
Let’s Watch!

10. The Dictyostelida- Cellular Slime Molds

11. Next: Thinking About Real Fungi

12. General Characteristics??

13. The Fungi: Structural Organization

14. Sexual Reproduction in Fungi
In sexually reproducing fungi, the union occurs in two stages:
1. Plasmogamy- fusion of the parents’ cytoplasm
2. Karyogamy- fusion of haploid nuclei of the two parents
During the time lag (minutes to centuries!) the mycelium is a heterokaryon
Occasionally the haploid nuclei pair off, two to a cell. This mycelium is dikaryotic.

15. Evolution of the Fungi

16. Zygomycete Life Cycle
Life Cycle of the black bread mold Rhizopus

17. Famous Zygomycota The black bread mold, Rhizopus
The dung fungus, Pilobolus

18. Evolution of the Fungi

19. The Ascomycota (Sac Fungi)
30,000+ species from marine, freshwater, and terrestrial habitats
Unicellular yeasts to large elaborate morels!
Many live with algae as lichens, may also form mycorrhizae with plants, or between cells in leaves!

20. Ascomycetes

21. The Basidiomycota- Club Fungi
~30,000 fungi including mushrooms, shelf fungi, puffballs, and rusts & smuts
Important decomposers (lignin!), also form mycorrhiza

23. Most vascular plants are associated with mycorrhizae.
Photo: ectomycorrhizal fungi (Hebeloma and Lactarius species) around the bases of birch trees; helios.bto.ed.ac.uk

24. Ectomycorrhizae
Ectomycorrhizae occur in almost all tree species in temperate and boreal forests. Short growing seasons in these areas limit decomposition and create nitrogen stress. The fungi release peptidases (exoenzymes) that break down proteins, releasing N-containing compounds.

25. Endomycorrhizae
Endomycorrhizae are found in ~80% of all plants, especially in warm/tropical grasslands and forests. They help supply phosphorus to the plants.

26. Ecological Adaptations in the Fungi
Lichens-
Symbiotic association of millions of algae or cyanobacteria within a mesh of fungal hyphae (most commonly ascomycetes)