kingdom fungi 11

Main Characteristics of Fungi

Although often mistaken for plants, fungi are unique from both plants and animals

Mostly Multicellular except unicellular yeast

NO photosynthesis: heterotrophic

Mostly terrestrial- there are some marine fungi

Mostly decomposers (recycle nutrients)

Cell wall made from chitin (a complex carbohydrate)

reproduce sexually and asexually using spores

Lack true roots, stems and leaves

Some are edible while others are poisonous

General Structure of Fungi

Fungi are filamentous structures.

Composed of filaments called HYPHAE (elongated cells with nuclei that form a branching filamentous structure)

Many hyphae are divided into individual cells by cell walls called SEPTA.

Mycelium

multiple hyphae forming a branching network of filaments is called a MYCELIUM (typically the part growing underground. Not always)

Reproductive Structure

The fruiting body is the part of a fungi that will house the reproductive structures (spores)

How do Fungi obtain Nutrients?

Fungi digest their food OUTSIDE their body – extracellular digestion

Fungi grow beside or on their food source

They excrete digestive enzymes into the surrounding environment

These enzymes breakdown their food into simpler molecules that can be absorbed into the hyphae

Known as saprobic (referring to dead matter) heterotrophs

REPRODUCTION of fungi

Most fungi reproduce Asexually and Sexually by spores

ASEXUAL reproduction is most common method & produces genetically identical organisms

Fungi reproduce SEXUALLY when conditions are poor & nutrients scarce. This creates genetically diverse offspring.

Spores (fungi)

Spores are an adaptation to life on land

Ensure that the species will disperse to new locations

Each spore contains a reproductive cell that forms a new organism

Nonmotile on their own

what are spores made out of 

Spores are made of:

Dehydrated cytoplasm

Protective coat

Haploid cell – single set of chromosomes (amount of DNA)

Wind, animals, water, & insects spread spores

Spores germinate when they land on a moist surface (new hyphae form)

Three types of Asexual Reproduction

Fragmentation – part of the mycelium becomes separated & begins a life of its own

Budding – a small cell forms & gets pinched off as it grows to full size

Used by yeasts

Asexual spores – production of spores by a single mycelium

Classification by Nutrition - fungi

Saprobes

-Decomposers

-Molds, mushrooms, etc.

Parasites

-Harm host

-Rusts and smuts (attack plants)

Mutualists

-Both benefit

-Lichens

-Mycorrhizas

Phylum: Ascomycota

Key Features:

sexual spores formed in sac-like “ascus”

Important to humans for fermentation, and food

Very diverse phylum

characteristics: 

Called Sac fungi

Includes Cup fungi, morels, truffles, yeasts, and mildew

May be plant parasites (Dutch elm disease and Chestnut blight)

Reproduce sexually & asexually

Ascus - sac that makes ascospores in sexual reproduction

Uses

Truffles and morels are edible ascomycetes

Penicillium mold makes the antibiotic penicillin.

Some ascomycetes also gives flavor to certain cheeses.

Saccharomyces cerevesiae (yeast) is used to make bread rise and to ferment beer & wine.

Phylum: Basidiomycota

Key Features:

Commonly called CLUB fungus

Produce “mushroom-cap” fruiting bodies

Mostly decomposers

characteristics: Called Club fungi

Includes:

Mushrooms

Toadstools

Bracket & Shelf fungi

Puffballs

Stinkhorns

Rusts and smuts

uses: Some are used as food (mushrooms)

Others damage crops (rusts & smuts)

Phylum: Zygomycota

Key Features:

Mostly soil fungi

Includes bread and fruit molds (powdery molds)

Decompose soil, plant matter and dung

Most commonly forms “molds”

Phylum: Chytridiomycota

Key Features:

Mostly decomposers – biodegrade and recycle nutrients

Some have “swimming spores”

zoospores (motile cells) with a single, posterior, whiplash structure (flagellum)

Ex. Allomyces – a water mold

Phylum: Glomeromycota

Key Features

All form symbiotic relationships with plant roots

Form spores.

Are all mutualistic with plants

Can for relationships with plants and bacteria.

Grow on plant roots and actual help plants to obtain nutrients such as phosphorus

Symbiotic Relationships in Fungi

Fungi receives sugar from the roots and in return sends nutrients and water to plant

Lichen

Partnership between fungus and cyanobacteria, or green algae

Fungus provides structure, can digest / absorb nutrients and water and can protect from harsh conditions

Cyanobacteria or algae produce sugar (food)

Mycorrhizae

Partnership between fungus and plant roots

Fungus provides increased capacity for absorption of nutrients and water

Plant produces sugar (food)