Ch 11 Section 2 Fungi

Ch 11 Section 2 Fungi

Fungi • Eukaryotic consumers • Come in a variety of shapes, sizes and colors

Hidden from View • Hyphae- chains of cells that make up multicellular fungi • Mycelium- a twisted mass of fungal hyphae that have grown together

Consumers • Fungi are consumers that cannot eat or engulf food. • They must live on or near their food supply

Getting Food • Most fungi obtain nutrients by secreting digestive juices onto the food source, then absorbing the dissolved substances • Many are decomposers

Roots with fungi • Some fungi live in symbiotic relationships with other organisms • On roots of plants – produce acid to change the minerals in the soil

Fungi cytoplasm • Holes in the cell walls of fungi allow the cytoplasm to move between cells throughout the organism

Reproduction • Asexual or sexual • Asexual • Hyphae breaks apart and each new piece becomes a new individual • Production of spores

Reproduction • Spores – a small reproductive cell protected by a thick wall • Sexual • Fungi produce sex cells from special structures that join to form new individuals

Kinds of Fungi • Threadlike Fungi • Molds- a shapeless, fuzzy fungus • Most live in the soil and are usually decomposers

Threadlike fungi • Reproduce asexually by forming sporangia, extensions of the hyphae that produce spores

Threadlike Fungi • Reproduce sexually by hyphae from different individuals join and develop into specialized sporangia

Sac Fungi • Largest group of fungi, includes yeast, powdery mildew, truffles and morels • Reproduces sexually by forming a sac called an ascus • Sexually produced spores develop within the sac

Yeast • Most are multicellular but yeasts are single celled • Yeast reproduce asexually by budding, a new cell pinches off from an existing cell

Uses • Yeast is used for making bread • Truffles and morels are prized edible sac fungi

Club Fungi • Most familiar group • Umbrella shaped • During sexual reproduction, special hyphae develop and produce clublike structures called basidia

Club Fungi • Sexual spores develop inside the basidia • The mushroom you know is only the sexual spore forming part of the organism which form at the edge of the mass of hyphae, usually in a circle

Club Fungi • Most familiar, basidia form in the grooves or gills under the mushroom cap • Other types of club fungi include bracket fungi, puffballs, smuts, and rusts

Imperfect Fungi • Includes the fungi that doesn’t fit into the other groups • Do not reproduce sexually • Most are parasites that cause disease in plants and animals

Imperfect Fungi • Athletes foot – fungus on the skin • One kind produces a toxin called aflatoxin, which can cause cancer • Used to make penicillin, cheese, soy sauce and citric acid for soft drinks

Lichens • Combination of fungus and an alga that grow intertwined and exist in a symbiotic relationship • Producers

Lichens • Resist drying out because they are protected by the fungi cell wall • Need only water, air and minerals, so they can grow on rocks

Lichens • They produce acids that break down the rock and cause cracks, which become filled with bits of rock and dead lichens, making soil for other things to grow on

Lichens • Absorb water and minerals from the air, making them sensitive to air pollution

Ch 11 Section 2 Fungi