1. Fungi

2. Shared Characteristics
Distinctive fungal features
Fungi are heterotrophs.
Fungi have several cell types.
Some fungi have a dikaryon stage.
Two haploid cells coexisting in a single cell (dikaryon) before fusion to form nucleus (diploid)
Fungi have cell walls that include chitin.
Fungi undergo nuclear mitosis.
In mitosis, nuclear membrane does not breakdown, mitosis occurs in the nucleus

3. The Body of a Fungus
Fungi exist mainly in the form of slender filaments (hyphae).
long chains of cells joined end-to-end divided by cross-walls (septa)
rarely form complete barrier
cytoplasm freely streams in hyphae
mycelium - mass of connected hyphae
grows through and penetrates substrate

4. The Body of a Fungus
Fungi cell walls are formed of polysaccharides and chitin.
not cellulose like those of plants
Mitosis is unique.
nuclear envelope does not break down and re-form
spindle apparatus formed within
spindle plaques take place of centrioles

5. How Fungi Reproduce
Differ from most animals and plants in that each compartment of hypha can contain one, two or more nuclei
monokaryotic - each compartment has a single nucleus
dikaryotic - two distinct nuclei within each hyphae compartment

6. How Fungi Reproduce
Fungi are capable of both sexual and asexual reproduction.
Fungi reproduce sexually after two hyphae of opposite mating type fuse.
in some fungi fusion two haploid cells immediately results in diploid cell (2n)
basidiomycetes and ascomycetes have dikaryotic stage (1n + 1n) before parental nuclei fuse to form diploid nucleus

7. Hyphal growth from spore
germinating
spore
mycelium
Mycelia have a huge surface area

9. Four Major Groups of Fungi
Chytridiomycota
Zygomycota
Basidiomycota
Ascomycota

10. Chytridiomycota
aquatic, flagellated fungi
most closely related to ancestral fungi

12. Zygomycota
includes common bread molds
produces temporarily dormant zygosporangia
sexual reproduction occurs by fusion of gametangia
asexual reproduction most common
hyphae produce clumps of erect stalks - sporangiophores
form sporangia

16. The life cycle of the zygomycete Rhizopus (black bread mold)

17. Zygomycota

18. Ascomycota
Very large group including yeasts, common molds, and morels
Named for reproductive structure ascus
haploid zygotic nucleus formed within
asci differentiated with ascocarp
Asexual reproduction takes place in conidia spores at the end of conidiophores.

19. A moldy orange (left), Penicillium (right)

21. Penecillium
Conidiophores carrying Conidia

22. Antibiotics المضادات الحيوية

27. Ascomycota

28. Sac Fungi: Ascomycetes - Life cycle

29. Ascomycota
Yeasts
unicellular - most reproduction is asexual and takes place by cell fission or budding
ferment carbohydrates
play a leading role in genetic research

33. Basidiomycota
Most familiar fungi (mushrooms, toadstools, puffballs, rusts, and smuts)
named for characteristic sexual reproductive structure, basidium
Four haploid products of meiosis incorporated into basidiospores
Mycelium made up of monokaryotic hyphae is called primary mycelium.
fusion of different mating types forms dikaryotic, secondary mycelium.

35. Gills (reproduction)

38. Basidiomycota

39. The life cycle of a mushroom-forming basidiomycete

41. Ecology of Fungi
Mutualistic associations
lichens - fungi and green algae
mycorrhizae - fungi and plant roots

42. Lichens
Lichens are symbiotic associations between a fungus and a photosynthetic partner.
usually ascomycetes
Specialized fungal hyphae penetrate photosynthetic cells and transfer nutrients to fungal partner.
Durable fungus, combined with photosynthetic properties, has enabled lichens to invade harsh climates.
extremely sensitive to pollutants

46. Mycorrhizae
Roots of about 90% of all kinds of vascular plants are involved in mutualistic symbiotic relationships (mycorrhizae).
arbuscular mycorrhizae - fungal hyphae penetrate outer cells of plant root
most common
ectomycorrhizae - hyphae surround, but do not penetrate, cell walls of roots

47. Mycorrhizae