1. The Fungi
Chapter 23
Mader: Biology 8th Ed.

2. Symbiotic Relationships
Outline
Characteristics
Structure
Reproduction
Evolution
Sac Fungi
Yeasts
Club Fungi
Smuts and Rusts
Imperfect Fungi
Symbiotic Relationships
Mader: Biology 8th Ed.

3. Characteristics of the Fungi
Kingdom Fungi contains the fungi.
Mostly multicellular eukaryotes that share a common mode of nutrition.
Heterotrophic
Cells release digestive enzymes and then absorb resultant nutrient molecules.
Some are parasitic.
Several have mutualistic relationship.
Mader: Biology 8th Ed.

4. Yeasts are best known example of unicellular fungi.
Structure of Fungi
Yeasts are best known example of unicellular fungi.
Body (thallus) of most fungi is multicellular mycelium.
Network of hyphae give the mycelium a large surface area per unit volume.
Mader: Biology 8th Ed.

5. Mycelium of Fungi
Mader: Biology 8th Ed.

6. Fungal cells are quite different from plant cells.
Structure of Fungi
Fungal cells are quite different from plant cells.
Lack chloroplasts and have a cell wall containing chitin and not cellulose.
Energy reserve is glycogen, not starch.
Nonmotile
Septate fungi have cross walls in their hyphae.
Nonseptate fungi are multinucleated.
Mader: Biology 8th Ed.

7. Both sexual and asexual reproduction occur.
Reproduction of Fungi
Both sexual and asexual reproduction occur.
Fungal sexual reproduction involves three stages:
Haploid Hyphae
Dikaryotic Stage
Diploid Zygote
Mader: Biology 8th Ed.

8. Hyphae that contains paired haploid nuclei is said to be dikaryotic.
Reproduction of Fungi
During sexual reproduction, hyphae from two different mating types fuse.
Hyphae that contains paired haploid nuclei is said to be dikaryotic.
Fungal spores germinate directly into haploid hyphae without embryological development.
Asexual reproduction usually involves the production of spores.
Unicellular yeasts reproduce by budding.
Mader: Biology 8th Ed.

9. Produce spores with sporangia.
Evolution of Fungi
Has been suggested fungi evolved from red algae because both fungi and red algae lack flagella in all stages of the life cycle.
Zygospore Fungi
(phylum Zygomycota) are mainly saprotrophs living off animal and plant remains.
Produce spores with sporangia.
Name refers to the zygospore seen during sexual reproduction.
Mader: Biology 8th Ed.

10. Most are composed of septate hyphae.
Sac Fungi
Most sac fungi (phylum Ascomycota) are saprotrophs that digest resistant materials containing cellulose, lignin, or collagen.
Most are composed of septate hyphae.
Ascus refers to the fingerlike sac that develops during sexual reproduction.
Asci usually surrounded and protected by sterile hyphae within an asocarp.
Asexual reproduction involves production of conidiospores.
Mader: Biology 8th Ed.

11. Term yeasts is generally applied to unicellular fungi.
Many are ascomycetes.
Budding is common form of asexual reproduction.
Sexual reproduction results in the formation of asci and ascospores.
When some yeast ferment, they produce ethanol and carbon dioxide.
Mader: Biology 8th Ed.

12. Yeast Cells
Mader: Biology 8th Ed.

13. Club fungi (phylum Basidomycota) include mushrooms and bracket fungi.
These are fruiting bodies called basidiocarps.
Contain basidia, club-shaped structures that produce basidiospores.
Usually reproduce sexually.
Mader: Biology 8th Ed.

14. Club Fungi
Mader: Biology 8th Ed.

15. Smuts and rusts are club fungi that parasitize cereal crops.
Great economic importance because of annual crop losses.
Do not form basidiocarps.
Life cycle often requires two different plant hosts to complete the cycle.
Mader: Biology 8th Ed.

16. Smuts and Rusts
Mader: Biology 8th Ed.

17. Produced at tips of modified aerial hyphae.
Imperfect Fungi
Imperfect fungi (phylum Deuteromycota) always reproduce asexually by forming conidiospores.
Produced at tips of modified aerial hyphae.
Known as imperfect in the sense that a sexual stage has not yet been observed.
Penicillium - Penicillin
Aspergillus - Soy sauce
Candida albicans- Yeast infections
Mader: Biology 8th Ed.

18. Penicillium
Mader: Biology 8th Ed.

19. Symbiotic Relationships
Lichens
Association between a fungus and a cyanobacterium or green alga.
Specialized fungal hyphae penetrate photosynthetic cells and transfer nutrients directly to the fungus.
Can live in areas of extreme conditions and contribute to soil formation.
Mader: Biology 8th Ed.

20. Lichen Morphology
Mader: Biology 8th Ed.

21. Help plants acquire mineral nutrients.
Mycorrhizas
Mycorrhizas are mutualistic relationships between soil fungi and the roots of most plants.
Help plants acquire mineral nutrients.
Give plant greater absorptive surface.
Mader: Biology 8th Ed.

22. Symbiotic Relationships
Review
Characteristics
Structure
Reproduction
Evolution
Sac Fungi
Yeasts
Club Fungi
Smuts and Rusts
Imperfect Fungi
Symbiotic Relationships
Mader: Biology 8th Ed.

23. Mader: Biology 8th Ed.