Fungi-What is that yellow blob

I. Introduction

• A. Early biologists used to think Fungus related to plant kingdom– 1. relatively immobile– 2. cell walls– 3. eucaryotic– 4. multicellular

B. Others thought Fungi related to animals

• 1. heterotrophic-although absorptive– a. Saprobes are decomposers that use dead matter– b. Parasites are absorptive on living matter (80% of

plant diseases)

• 2. cell walls made of chitin• 3. molecularly resemble animal kingdom

more

• 4. some of the fungi are aseptate??• 5. they are known as the coenocytic fungi-

continuous cytoplasmic mass with thousands of nuclei

• 6. produced with karyokinesis with no cytokinesis

• 7. haustoria-found in the parasitic fungi• a. specialized hyphal tips that invade the

living tissues to absorb nutrients• b.

http://helios.bto.ed.ac.uk/bto/microbes/scurf2.jpg

C. Fascinating and unusual creatures

1. Predators on round worms

I just can’t seem to get loose

2. Pilobolus• 1. decomposes in animal

dung• 2. bends its sporangia

bearing hyphae toward light• 3. where grass will likely be

growing• 4. land and stick to grass

upwards of two meters away• 5. must be ejected long

ways away as cows won’t graze in neighbor of own dung

• 6. grass ingested by herbivores and spores are distributed in dung

Internet can be crazy• Found this dance

troupe when looking for Pilobolus fungi

Other interesting fungi

Other interesting fungi

II. Terminology

• A. Hyphae• 1. tubular walls surrounding

plasma membranes• 2. most fungi are multicellular

with the Hyphae being divided into separate cells by septa

• 3. the septa have pores through their end walls through which cytoplasm can move from cell to cell

• 4. most of the cell wall is composed of chitin similar to the material making up the exoskeletons of insects

A. Hyphae cont.• 5. some of the fungi are aseptate??• 6. they are known as the coenocytic

fungi-continuous cytoplasmic mass with thousands of nuclei

• 7. produced with karyokinesis with no cytokinesis

• 8. haustoria-found in the parasitic fungi

• specialized hyphal tips that invade the living tissues to absorb nutrients

B. Mycelium-an interwoven matt of hyphae

• 1. very difficult to imagine the size of a fungal mycelium• 2. hyphal threads are spread throughout its food source

and also subterranean• 3. can be huge-Billy Fucillo• 4. one giant individual in Oregon-you thought might be

in Texas• a. 3.4 miles in diameter• b. 2200 acres of forest• c. Super Bowl Time 1600 football fields• d. 2400 years old• e. can add a kilometer of Hyphae a day

C. Plasmogamy

• 1. Two opposite mating types of hyphae fusing togeth

• 2. produces a dikaryotic hyphae

• 3. hyphae referred to as heterokaryon

• 4. dikaryotic hyphae produces a fruiting body

• 5. different fruiting bodies are used to separate fungi into their different groups

D. Fruiting bodies-site of karyogamy and meiosis

• Basidiocarp of Basidiomycota

Ascomycota

• Ascocarp

Zygomycota

• Zygosporangium

III. Three divisions of fungi in lab

• A. Zygomycota• B. Ascomycota• C. Basidiomycota

A. Zygomycota Life Cycle

Gametangia and zygosporangia

B. Ascomycota

• 1. some are partners with algae forming the symbiotic lichen world

• 2. macroscopic fruiting bodies called ascocarps-the ascocarps house the asci (pl)/ascus(sing)

• 3. compared to the zygomycota, the ascomycota form a more developed heterokaryon stage

• 4. the heterokaryon stage forms ascocarps

Ascomycota (cont)

• 5. the ascocarps house the asci in which meiosis takes place

• 6. the asci imposes an order to the meiotic division so that you can distinguish meiosis I from meiosis II

7. Ascomycota can also reproduce asexually in good weather to greatly increase their reproductive potential

• asexual spores are produced at the external tips of conidiophores-the naked spores are called conidia

C. Basidiomycota Life Cycle-mushroom

Boletus

Gills with basidia

Microscopic view of gills with basidiospores

• This is one small piece of a gill

• Imagine the number of basidiospores that one mushroom produces in its lifetime

Basidiocycota