Bio153_lecture10_Fungi_sv - Fungi What is the Largest...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Fungi What is the Largest Organism in the World? Armillaria ostoyae Prototaxites Why Do Biologists Study Fungi? • Useful laboratory model: genetic control of cell division in eukaryotes (yeasts) • fungi nourish plants • critical to the carbon cycle on land • ecological and economic benefits • some cause debilitating diseases Fungi Feed Land Plants Mycorrhizal associations between fungi and roots of land plants absence of saprophytic fungi resulted in the formation of coal & peat deposits (Carboniferous period) • peatlands – acidic • coal-forming swamps – acidic Fungi Speed Up the Cycling of Carbon on Land Atmospheric CO 2 Release of CO 2 from cellular respiration by plants, animals, fungi, and other organisms Fixation of CO 2 by plants P la n ts F u g i A im a ls Fungal mycelia convert cellulose and lignin (from wood) into sugars and other small organic compounds
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fungi Function as Decomposers saprophytes: release nutrients such as nitrogen and phosphorus needed by living organisms break down lignin and cellulose Benefits to Humans • soil fungi: source of drugs • cyclosporin, penicillin • source of food Parasitic Fungi • virtually all animals & plants are susceptible • plant pathogens; blights, mildews, smuts, rusts Characteristics of Fungi • lack plastids: • chitin • threadlike, filamentous bodies •g l y c o g e n • mostly terrestrial Morphological Traits: Fungi Have Two Growth Forms Single-cel ed fungi are cal ed yeasts. Multicel ular fungi have weblike bodies cal ed mycelia. (1) single-celled forms— yeasts (2) multicellular, interconnected fungal hyphae— mycelia Some fungi adopt both forms Multicellular Fungi Have Unusual Bodies Hyphae are usually broken into compartments by septa. Both the reproductive structure and mycelium are composed of hyphae. Cell wall Septum
Background image of page 2
Filaments in mycelium are called hyphae: 2 types: 1. septate (cross-walls, called septa) separate compartments with a nucleus) 2. coenocytic (cytoplasm with many nuclei) most hyphae are haploid some are heterokaryotic The Nature of the Fungal Mycelium • Mycelia: composed of branching networks of very thin hyphae: high surface-area-to-volume ratio • Advantage: • Disadvantage: •“ fairy ring”: outward growth of mycelium; appearance of fruiting bodies - mycelia are an adaptation to … - reproductive organs are the only thick, fleshy structures that fungi produce Mycelia can be huge Four Major Groups of Fungi Based on Four Distinct Reproductive Structures Spore
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/01/2012 for the course BIOLOGY 153 taught by Professor Dr.arts during the Fall '10 term at University of Toronto- Toronto.

Page1 / 8

Bio153_lecture10_Fungi_sv - Fungi What is the Largest...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online