1. Fungi

2. Fungi
basidomycete, ascomycete
mold, chytrid, Aspergillus sp.

3. Fungi characteristics
Fungi are sessile heterotrophs
Important both ecologically and economically
Secrete enzymes which break down food and then absorb the food
some do this in the environment
some penetrate cells of other organisms and absorb nutrients from cells

4. Structure Either multicellular or unicellular (yeast)
some yeast are sort of multicellular because they connect in strings forming “pseudohyphae” (many molds)
Most multicellular fungi have hyphae – cells surrounded by a tubular cell wall made of chitin.
The primary structure of fungi
In most fungi, the mass of all non-sexual hyphae is called a “mycelium”. In mushrooms, the sexual part is the above ground part. Many mycelium are underground
most hyphae are divided by cross walls called septa that divide the hyphae
Septa have pores that allow many parts of the cells to flow back and forth between cells on either side of the septum

6. from mitosis w/o cytokinesis
mycorrhizae
specialized hyphae that allow absorption from other organisms

7. Mycorrhizae symbiosis between fungus and plants (at the roots)
plants provide constant source of carbs (glucose)
fungus provides ability to fix nutrients like nitrogen so
they may be absorbed.
legumes
found in many plants

8. Fungi

9. Evolution of Fungi

10. “Arbuscular mycorrhizal”

11. “AM” - many are parasitic - chytridiomycosis major cause of
amphibian decline worldwide
Chitosan instead of chitin
specialized spores
bread mold
230 species
mycorrhizae
“AM”
-brewers yeast, bakers yeast, Penicillium,
morels, truffles.
-much evidence to support monophyly
-posses “ascospores” for reproduction
Septate
- most of the familiar fungi – all the muschrooms, smuts, rusts, puff balls,etc.
- reproduce via basidia (specialized reproductive cells)

12. Reproduction As part of their life cycle, fungi produce spores.
spores are tough reproductive cells
but much variation
One common process:
Spores produced by meiosis are carried on a clublike sporangium.
From these spores, haploid hyphae grow, and may give rise to asexual sporangia, special hyphae which produce spores without meiosis.

13. Reproduction Plasmogamy – Cytoplasm of 2 parent mycelia join
Karyogamy – Haploid nuclei from two parents fuse to produce diploid cells.
Cells with one cytoplasm and two nuclei are known as a dikaryon; meaning "two nuclei". Also called ‘heterokaryotic’.

14. Reproduction

15. Reproduction
no fusion of nuclei!

16. Reproduction

18. Chytrids aquatic microscopic flagellate reproductive cells
sometimes including in the water trapped around soil particles
microscopic
flagellate reproductive cells
lost in later fungi (doesn’t work well on land)

19. Zygomycetes (bread molds) named for large zygotes known as zygospores

20. Ascomycetes (yeasts, Penicillium)
Neurospora crassa
George W. Beadle and Edward L. Tatum
Showed that genes (proteins) control metabolic processes.

22. Basidiomycetes

23. Yeasts (Ascomycota and Basidiomycota)
Ascomycota contains the “true yeast”

24. Yeast characteristics
Single celled
Reproduction by budding or binary fission
E.g. yeast in baking Saccharomyces cerevisiae
E.g. Candida albicans pathogenic to humans

25. “AM” (Glomeromycetes)
~80% of plant species form symbiosis with

26. Lichens
Lichen – A symbiotic relationship between a fungi and a photosynthetic microorganism
Fungi form with green algae or cyanobacterium
Mostly Ascomycetes

27. Lichens (Ascomycetes)