Fungi

• What would a pizza be without mushrooms?

• The mushroom is the most recognizable organism in the Fungi kingdom. However, it is not the only one.

• Both mushrooms and moulds are classified in this kingdom because they share similar characteristics. Moulds are commonly found on food that has gone bad.

• Food left untouched for long periods of time will grow mould, perhaps like the sandwich at the bottom of your locker.

A quick word from our dear friend Hank

• https://www.youtube.com/watch?v=m4DUZhnNo4s

• Organisms in this kingdom are all eukaryotic and can contain multiple nuclei in a cell.

• Most fungi lack roots and are either anchored in soil or some other surface, like a tree.

• They can undergo asexual, sexual or both forms of reproduction.

• All fungi are heterotrophic and depend on other organisms for nutrition.

• This evolutionary development in fungi is the basis for the separation of fungi from plants.

Classification• Fungi are classified by the type of spores they

produce. (The classification term division replaces phyla in the Fungi kingdom).

• Fungi in the division Zygomycota produce spores that are covered by a case-like structure called sporangium.

• Spores that are encased in a sac-like structure called ascus are placed in the Ascomycota division.

• Club-like sacs called basidium are found in the Basidiomycota division.

Ascomycota Zygomycota

Basidiomycota

Feeding Habits• Fungi obtain their nourishment by absorbing

decaying organic matter from their environment. • Fungi secrete digestive enzymes that break down

the organic material and then absorb the digested food through their cell wall.

• Specialized structures called hyphae extend from the bodies of fungi and branch into filaments called mycelia (sing. mycelium).

• Mycelia are responsible for absorbing nutrients.

• The mycelium is generally too fine to be seen by the naked eye, except where the hyphae are very closely packed together.

• The picture on the right was taken using a microscope.

• The hyphae are magnified 100 times their actual size.

Reproduction• Fungi show variation in

their life cycle. • However they all produce

haploid (half genetic information) spores.

• In sexual reproduction these spores are carried by wind, and if conditions are favourable, they will begin to grow and germinate.

• Fungi can also reproduce asexually using the process of fragmentation.

• Fragmentation occurs when part of the mycelium of a fungal hyphae break away from its parent.

• Now, each broken fragment gives rise to a new mycelium.

Societal Uses for Fungi• Fungi play a key role in many aspects of industry

and the environment. • The production of bread, wine and beer

requires the presence of yeast cells to respire and produce carbon dioxide or ethanol.

• The natural decomposition of dead organic matter in ecosystems is dependent upon fungi.

• Penicillium is used as an antibiotic to fight off harmful bacteria.

• Pizza would not be the same without the presence of mushrooms.

• Not all fungi are beneficial. • Mould growing indoors in damp

wet environments can cause eye, throat and nose irritation.

• Athlete's foot, a fungal infection, develops on the feet and toes and causes reddened, cracked and peeling skin.

• Dutch Elm disease is currently affecting elm trees throughout Ontario and other areas of Canada.

Symbiotic Relationships• Relationships that are beneficial to both

parties are symbiotic. • Most fungi live in symbiotic relationships with

other non-fungal organisms. • Remember that fungi lack mobility and are

heterotrophic decomposers. Therefore they need to have a constant nutritional supply available.

• This is accomplished through the interaction of fungi with trees.

• Most trees have fungi living within their roots. This is called mycorrhiza.

• The hyphae absorb minerals from the soil and release them into the roots of the plants.

• Water uptake in plants is also increased with the presence of mycorrhiza as well as it helps to suppress diseases within plants.

• In return, the hyphae are able to extract sugars and proteins from the plant.

• Shown in the images on the right are two vines.

• The vine on the left does not have mycorrhiza and the vine on the right does have mycorrhiza.

• You can clearly see the positive influence fungi have on the growth of this vine.

Homework

• Life Cycle of a Mushroom• http://wps.prenhall.com/esm_freeman_biosci

_1/7/1953/500043.cw/index.html• Describe various characteristics of a specific

fungus such as classification, structure, habitat, reproduction, feeding habits, and environmental/societal relevance.

• Your given “fungus” is on the next slide

Madison PenicilliumKael Saccharomyces boulardiiMadeliene Lactobacillus acidophilusJacob Saccharomyces cerevisiaeJacqueline BifidobacteriaJennifer Pityrosporum ovaleMelanie Cryptococcus neoformansJamie AspergilusHarry RhizopusSarah PenicilliumJames Saccharomyces boulardiiJensyn Lactobacillus acidophilusSkylar Saccharomyces cerevisiaeMaria BifidobacteriaJakob Pityrosporum ovaleJared Cryptococcus neoformansHaiden AspergilusAmber Rhizopus