Chapter 21 Biology – Miller • Levine The Kingdom Fungi Chapter 21 Biology – Miller • Levine

What are Fungi? Once were classified as nonphotosynthetic plants Eukaryotes Heterotrophs Digest their food outside their body and then absorb the nutrients Have a cell wall made of chitin

Structure & Function of Fungi Except for yeasts, all fungi are multicellular Most are made of tiny filaments called hyphae Some have cross walls that divide the hyphae into cells

Structure & Function of Fungi Mycelium – thick, tangled mass of hyphae Provide large surface area Fruiting body – reproductive structure

Reproduction in Fungi Most reproduce both asexually & sexually Asexual reproduction Cells or hyphae break off Some produce spores Sporangia – structures that produce spores Sporangiophores – specialized hyphae that contain sporangia Spores are spread by the wind & by animals

Reproduction in Fungi

Reproduction in Fungi Sexual Reproduction Two mating types → “+” and “-” When a + fuses with a -, it forms a gametangium which forms gametes 2 gametangium fuse & form a zygote

Phylum Zygomycota The Common Molds Ex. Bread mold Rhizoids – rootlike hyphae that penetrate the surface Anchor the fungus, release digestive enzymes, absorb the nutrients Stolons – stemlike hyphae that run along the surface

Mold

Phylum Ascomycota The Sac Fungi Ex. Cup fungi, yeasts Ascus – saclike reproductive structure that contains spores

Phylum Basidiomycota The Club Fungi Ex. Mushrooms Basidium – club shaped reproductive structure that contains spores

Phylum Deuteromycota The Imperfect Fungi Ex. Penicillium These fungi do not appear to have a sexual reproduction stage

Fungi as Decomposers Break down decaying matter and wastes Saprobes – obtain food from decaying matter

Fungi as Parasites Cause serious plant and animal diseases Ex. Corn smut, wheat rust, athlete’s foot

Symbiotic Relationships Lichens – mutualistic relationship between a fungus and a photosynthetic organisms Mycorrhizae – mutualistic relationship between plant roots and fungi