Kingdom Fungi Kingdom Fungi Finding the Fungus Among Us

Characteristics of Fungi EukaryoticEukaryotic Most are MulticellularMost are Multicellular Filamentous body planFilamentous body plan Heterotrophic by AbsorptionHeterotrophic by Absorption Produce spores by sexual and asexual reproductionProduce spores by sexual and asexual reproduction Haploid for part or most of life cycleHaploid for part or most of life cycle Cell wall made of chitinCell wall made of chitin No movement: change location by growth of body or dispersion of sporesNo movement: change location by growth of body or dispersion of spores

The Filamentous Body of a Fungus (a) Mycelium (b) Individual Hyphae (c) Hyphal Cells (cutaway) Cell Walls Septum Pore Cytoplasm Haploid Nuclei

Body Plan of Fungi Mycelium = network of filamentsMycelium = network of filaments Hypha = individual filament (plural = hyphae)Hypha = individual filament (plural = hyphae) Septum = partition dividing cells, has pore for distribution of nutrientsSeptum = partition dividing cells, has pore for distribution of nutrients Reproductive structure extends from main body, produces sporesReproductive structure extends from main body, produces spores

Fungal Nutrition HeterotropicHeterotropic by absorption –secrete –secrete digestive enzymes –digest –digest macromolecules outside the body –absorb –absorb digested nutrients ThreeThree nutritional modes –Saprophytic –Saprophytic = digestion of dead organisms –Parasitic –Parasitic = digestion of live organisms, causing disease –Mutualistic –Mutualistic = beneficial relationship for two independent organisms

Saprophytes

Parasites

Lichen: Mutualism Between Alga and Fungus Algal Layer Fungal Hyphae Attachment Structure

Mycorrhizae: Mutualism Between Fungus and Plant Roots

Sexual Reproduction HyphaHypha from mycelia of opposite mating types fuse FusionFusion of two haploid nuclei forms diploid zygote ZygoteZygote produces haploid spores by meiosis EachEach spore germinates to produce a haploid mycelium

Chythrid Fungi Flagellated,Flagellated, swimming spores require water for dispersal AncestralAncestral group, gave rise to modern fungi Forming Male Gametes Forming Female Gametes

Zygote Fungi LiveLive in soil and on decaying plant matter ZygoporangiaZygoporangia = reproductive structures producing haploid spores

Sac Fungi AscusAscus = sac that surrounds haploid ascospores

Club Fungi BasidiumBasidium = club-shaped reproductive structure that produces basidiospores

Club Fungus Life Cycle Diploid 2 n Haploid 1 n Mushroom gills bear reproductive basidia. Basidia on gills Haploid Nuclei Fusion forms diploid zygote. M E I O S I S Basidiospores (haploid)

Club Fungus Life Cycle Diploid 2 n Haploid 1 n Basidia on gills Basidiospores (haploid) “+” Mating Strain “-” Mating Strain Basidiospores germinate forming hyphae (haploid). + - Hyphae fuse, but haploid nuclei remain separate in binucleate cells Hyphae aggregate to form mushroom

Imperfect Fungi SexualSexual reproduction has not been observed