Fungi

•Multicellular except for yeast

•Cell walls made of chitin (study guide question 3)

•Some with multinucleate cells and incomplete cell walls (see next slide)

•Mycelium – body of the fungus (study guide question 2 & 4)

•Hyphae – filaments that make up the mycelium (study guide question 2 & 4)

•Classified by method of sexual reproduction; can also reproduce asexually

• -Myco or -mycete = fungi

•Heterotrophic by absorption

•Decomposer (saprophyte) - feeding on dead and decaying organisms or parasitic – living in or on another organism, possibly causing disease (study guide question 5)

•NO chlorophyll! NOT photosynthetic (study guide question 1)

Fungal hyphae showing some with cell walls and some without

Note the pore through the cell wall allowing cytoplasm to move from cell to cell to bring nutrients from one end of the organism to the other

Question 2 & 4 in the study guide:

Kingdom Fungi

Three phyla of fungi, based on method of sexual reproduction:

•Zygomycota

•Basidiomycota

•Ascomycota

•Use the information in the following slides to complete the table in your notes.•Note that some fungi are classified as Deuteromycota or Fungi Imperfecti because the method of sexual reproduction has not been discovered. When it is, they will be placed in the appropriate phylum.

Protist that gave rise to the fungi

Summary of Fungi Reproduction

Spore – reproductive cell that is resistant to environmental conditions and that can develop into an adult without fusion with another cell (asexually)

Zygomycota•Fungi that reproduce with zygosporangia – structures resistant to freezing and drying, allowing the organism to live through “tough times”

•Have no walls in their hyphae (multinucleate cells)

•Ex) Pilobus (top picture) can aim its sporangia toward light where grass is likely to be growing, then shoot spores to the grass. Important because they depend on grazing animals, like cows, to scatter the spores through feces.

•Ex) Rhizopus stolonifer - black bread mold (bottom picture); diagram p. 485

Basidiomycota – club fungi

•Fungi that reproduce with basidia (an external club-like structure found under the cap of a mushroom) that bear spores

•Hyphae are divided by walls, but usually walls are incomplete so cytoplasm can still move from cell to cell; important in “eating”

•Ex) mushrooms, puffballs, rusts, smuts, shelf fungi

Stinkhorn fungus

mushroom

Shelf fungus

Fairy ring – results from the outward growth in all directions of a basidiomycete (mushroom); the structures visible above the ground are the reproductive structures; the body of the fungus (mycelium) is in the ground

Examples of basidiomycetes

Rusts, smuts, & ergotsErgots – can cause gangrene, nervous spasms, burning sensations, hallucinations, temporary insanity, and death when accidentally ingestedIn 944 A.D. more than 40,000 people died in France from ergot poisoning. It contains one of the active ingredients found in LSD.

Oddly enough, it has been used for medicinal purposes in treating high blood pressure and stopping maternal bleeding following childbirth

Fun Fungi Fact:

Some of the “witch hunts” of 17th century America have been attributed to ergot poisoning as it is a common pest in rye.

Ascomycota – sac fungi

•Fungi that reproduce with internal sac-like structures called asci that are full of spores

•Hyphae are divided by walls, but usually walls are incomplete so cytoplasm can still move from cell to cell; important in “eating”

•Ex) cup fungi, yeast, morels, truffles (not chocolate ones!)

Truffle – worth $600 a pound

An edible morel

Yeast budding(study guide question 8)

Yeast are ascomycetes

Budding – asexual reproduction

Mold

Penicillium - an ascomycete commonly called “mold” that naturally produces an antibiotic

Note the zone of inhibition around this Penicillium

bacteria

What color are fungi NOT? What is missing in the fungi that would make them that color? (Hint: look at the autotrophic, multicellular organism with cellulose in its cell walls surrounding many of these fungi)

HOW is that evidence that fungi are heterotrophic? What is missing in the fungal cells that are present in the other organism’s cells????

Answer: Green, CHLOROPHYLL

Answer: No cholophyll means no chloroplasts. No chloroplasts means no photosynthesis. No photosynthesis means heterotroph.

Fungal Partnerships

Symbiotic relationship – one in which two species live together in a close, long-term association

ex) mutualism – both benefit (mycorrhizae & lichens)

ex) parasitism – host organism is harmed, the parasite benefits

ex) commensalism – one organism is neither harmed nor benefits, the other benefits

Fungi are heterotrophic. Parasitic fungi penetrate a living organism with specialized hyphae to allow the fungus to absorb nutrients from its host.

Other fungi can prey on organisms that wander into its path by trapping the prey with specialized hyphae upon contact and then penetrating the organism with a different type of hyphae (nematode caught by fungus)

Lichen – mutualistic relationship between a photosynthetic organism and a fungus

- important pioneer species, especially in primary succession

Effects of mycorrhizae(word parts – “fungus root”) on plant growth

Mycorrhizae – mutualistic relationship between a fungus and a plant root

- the plant supplies the fungus with carbohydrates while the fungus absorbs phosphorus and other minerals from the soil and passes them to the plant, which would be unable to get these minerals without mycorrhizae

- fossilized plants have mycorrhizae, showing that they probably couldn’t have moved on to land without fungi!

Fun Fungus Fact: Most mushrooms that grow at the base of trees are actually the reproductive structures of mycorrhizae

Plant without Plant with

mycorrhizae mycorrhizae

•Molecular evidence from comparisons of several proteins and ribosomal RNA indicates that fungi are more closely related to ANIMALS than to plants.

Remember the chitin!!!!

Important Fungal Traits

Principal decomposers

Pioneer species

Pollution indicators (p. 492)

Nitrogen fixers

Symbionts

Antibiotic producers

Also, flavor cheese, make bread rise, used in beer brewing, & wine making, as well as providing a food source for many organisms (mushrooms!)