21-1: The Kingdom Fungi
A. What Are Fungi?
Fungi include MANY DIFFERENT types of organisms
From tiny yeast cells
To the one of the largest organisms in the world!
Multicellular (except for yeasts)
Decomposers: decompose dead and decaying material
-Secrete enzymes OUTSIDE bodies
- Absorb digested nutrients
Hyphae: long, slender, root-like filament
Septa: cross-walls across hyphae (not in all hyphae)
Mycelium: mat of interwoven hyphae
o Large surface area = max food absorption
Fruiting body: reproductive structures, like mushrooms
o Many can develop from same mycelium
o “fairy rings”
Entire mycelium is haploid!
o (1 set of chromosomes)
B. Structure & Function of Fungi
Fungi cells have cell walls
-Contain carbohydrate “chitin” also found in exoskeletons Unlike plants:
-Fungi DON’T have chlorophyll
-Fungi have chitin in cell walls (plants have cellulose)
C. Reproduction in Fungi
Most fungi reproduce BOTH asexually and sexually
Sporangia at the tip of sporangiophores produce haploid spores Fragmentation (breaking off) of hyphae can also produce new mycelia
Fungi form hyphae of opposite “Sex”
o Called “+” & “-“
The + & - hyphae fuse and form gametangia:
o Makes gametes
o Form a diploid zygote
o Zygote undergoes meiosis: haploid once again!
D. How Fungi Spread
Fungal spores travel VERY easily in the air
All they need is a good “landing place” with moisture & food Some fungi have special adaptations for spreading spores
21-2: Classification of Fungi
A. 4 Phyla of Fungi:
Named for their reproductive structures!
B. Phylum Zygomycota
o On bread, cheese, etc.
Black bread mold: Rhizopus...