Chapter 20.1 Introduction to Fungi

Main Idea

!  Fungi are unicellular or multicellular eukaryotic heterotrophs that are decomposers

Characteristics of Fungi

! Most are mutlicellular (made of more than one cell)

!  Yeasts are only unicellular fungi (organism is only 1 cell)

Features of Fungi

! Chitin – the strong, flexible substance that makes up the outer wall of fungi

! Hyphae – the threadlike filaments that make up the body of a fungus

! Myceluim – a netlike mass of repeatedly branching hyphae

!  Fruiting body – reproductive structure of a fungi, the mushroom

Features of Fungi

! Septa – separate hyphae into cells ! Aseptate – hyphae with no septa,

one cell may have hundreds of nuclei

Fairy Ring

!  Fairy Ring Simulation

!  http://glencoe.mcgraw-hill.com/sites/0078759864/student_view0/unit5/chapter20/concepts_in_motion.html#

Nutrition ! Saprophytic – feeds on dead

organic waste, ex. Shelf fungi

Nutrition

! Parasitic – absorb nutritnts from the cells of a living organism, ex. Ringworm

! Mutualisitc – both the fungi and the other organism need each other to survive, ex. Fungi and plant roots

Reproduction of Fungi

!  Budding – exhibited in yeasts, asexual

!  Fragmentation – occurs when mycelium is broken off, asexual

!  Spore production – produces spores with a hard outer covering that will produces new hyphae, sexual and asexual

Adaptations for survival

!  Size and shape of spores – small and lightweight

! Number of spores produced !  Production of a sporangia – a sac

or case where spores are produced and protected until they are ready to be released

End of 20.1

Chapter 20.2 – Diversity of Fungi

Main Idea

!  Fungi exhibit a broad range of diversity and are classified into four major phyla

Classification

! Chytridomycota – the chitrids !  Zygomycota – the common molds ! Ascomycota – sac (or cup) fungi !  Basidiomycota – club fungi

Chytrids (Chytridiomycota)

! Mostly aquatic ! Have flagellated spores

Common Molds (Zygomycota)

! Stolons – the hyphae that spread over the surface of the food

! Rhizoids – the hyphae that penetrate the food and absorb nutrients

! Gametangium – sexual reproductive structure

! Zygospore – spore with hard covering that can stay dormant for a period of time

Life Cycle of Bread Mold

Asexual Reproduction

Sexual Reproduction

Sporangia

Gametangia

Zygospore

Spores

New Hyphae

Sac Fungi (Ascomycota)

! Has the most species of all phyla ! Can reproduce both sexually and

asexually ! Conidiophores – spore producing

hyphae ! Conidia – spores produced by

conidiophores ! Ascocarp – repruductive structure

Sac Fungi - Reproduction

! Ascus – saclike structure that houses the spores

! Ascospores – spores produced by an ascus

The Sac Fungi Reproduction

Sexual Reproduction

Asexual Reproduction

Conidiophore

Ascocarp

Ascus

Ascospores

Conidia

C

Club Fungi (Basidiomycota)

!  Saprophytic are decomposers of wood

! Rarely reproduce asexually

Club Fungi - reproduction

! Basidiocarp – the fruiting body, the sexual reproductive structure, the mushroom

! Grow very quickly due to cell enlargment rather than cell division

! Basidia – club shaped hyphae on the underside of the basidocarp that produces spores

! Basidiospores – spores released by the basidia

Club Fungi Reproduction

Basidiocarp

Basidia

Basidiospores

Imperfect Fungi - Deuteromycetes

!  Lack a sexual stage

The End Ch. 20.2

Ch. 20.3 – Ecology of Fungi

Main Idea

!  Lichens and mycorrhizae deomonstrate important symbiotic relationships between fungi and other organisms

Lichens

!  Lichens – a symbiotic relationship between a fungus and an alga

! Great diversity of these organisms !  Serve as bioindicators ! Bioindicator – a living organism

that is sensitive to changes in environmental conditions and responds to changing conditioners

Structure of a Lichen

Mycorrhizae

! Mycorrhiza – a symbiotic relationship between a specialized fungus and plant roots

Fungi and Humans

!  Benefits – medicine, penicillin

Fungi and Humans

!  Foods – ediable mushrooms, yeast in bread, alcohol in beer and wine, truffles, cheeses such as brie and bleu

!  Bioremediation – cleaning the environment of pollutants

Fungi and Humans

! Diseases caused by fungi can destroy plants and trees, ex. Corn smuts and wheat rust

!  Some fungi are parasitic to humans, ex. Ringworm and athletes foot

The End Ch. 20.3 – Ecology of Fungi