Fungi Chapter 19 I. Characteristics of Kingdom Fungi; A. Eukaryotic 1. parasites; haustoria invade hosts cells * ringworm and athletes foot 2. saprophytes; live off of dead organic matter 3. mutualists; live in symbiotic relationship B. Heterotrophic; extracellular digestion (enzymes dissolve food outside of the cell, then absorb the nutrients).

C. Structure; 1. Cell walls of chitin 2. Cells form strands of hyphae. Masses of hyphae form mycelium. D. Mostly multicellular, but some single celled such as yeast E. Reproduction; This is the characteristic used to classify most fungus phyla. 1. Sexual; Usually occurs when nutrients and/ or water become scarce. Mating type + (plus) combines with mating type – (minus).

2. Asexual; Usually occurs when nutrients and water are abundant. a. fragmentation; piece of mycelium breaks off, then continues to grow into an new fungus. b. budding; by mitosis, new cell is formed, and pinches off of the original cell. c. spores; reproductive cells produced in a structure known as a sporangium.

II. Classification; Most fungi are classified according to reproduction and/ or reproductive structures. A. Phylum Ascomycota (sac fungi); largest phylum, many unicelled species (yeast). 1. reproduction; a. sexual; ascospores develop inside a sac- like ascus. b. asexual; * budding- yeast * spores called conidia develop

2. importance; a. beneficial; yeast and morels are edible b. harmful; molds, ergot, ringworm and athlete’s foot. B. Phylum Basidiomycota (club fungi); this phylum contains the mushrooms 1. reproduction; Almost all reproduce sexually with basidiospores, produced in a structure known as a basidium

2. importance; a. beneficial; often used for food (mushrooms). b. harmful; many poisonous, many damaging to plants. C. Phylum Zygomycota (common molds); hyphae form rhizoids to anchor fungus to food source. Rhizoids- penetrate food source Stolons- connect rhizoids to one another. Spread across surface of the food source.

1. reproduction; mostly asexual repro. a. sexual; conjugation- gametangia produce a zygospore. b. asexual; sporangia releases spores, or fragmentation 2. importance; causes bread mold D. Phylum Deuteromycota (imperfect fungi); 1. reproduction; only asexual reproduction observed

2. importance; a. food production- bleu cheese, soy sauce E.; Mycomycota- mutualistic 1. Lichens- symbiosis between a fungus and an algae or cyanobacteria. a.Indicator of air pollution c. medicinal- penicillin b. food decomposers b. food source for many organisms

Wolf lichen (also known as wolf moss) used as dye

Reindeer lichen used as food

crustose

Foliose

Fruticose

2. Mycorrhizae- symbiosis between fungus and plant. a. important for most plants because they supply minerals for growth. b. important for the germination of some plant seeds. c. greatly increases the ability of plant roots to absorb water.