Module 7: Fungi

Fungi

heterotrophic eukaryotes

secrete powerful enzymes to digest their food externally

acquire their nutrients by absorption

• decomposers/symbionts

• breakdown and absorb nutrients from dead organisms

• obtain energy and nutrients from living photosynthetic organisms (lichen)

Made up of hyphae, which makes up mycelium

Indentifyable Traits of Fungi

1. Decomposers/symbionts (live with something else)

2. They are sessile (non-motile, do not move)

3. Chitin cell walls, chitin is also found in insect exoskeletons

Scoby

Symbiotic Culture Of Bacteria and Yeast

tan, fleshy symbotic mat of bacteria and fungi

makes kombucha

Mycelium

a mass/group of hyphae

mushroom part (many cells working together)

Hyphae

Threadlike cells that make up fungi

separated by cross-walls with pores large enough for ribosomes, mitchondria, and nuclei to cross

are sometimes multinucleate without cross-walls

have huge surface area to secrete digestive enzymes and aborbs food

surrounded by cell wal made of chitin, not cellulose

Mushroom

Reproductive mycelium

Mycorrhizae

represents symbiotic relationship between fungi and plant root cells

nonparasidic, mutual relationship

common in soil and are present at roots in nearly all vascular plants

mycorrhizal fungi absorb phosphorus and other essential materials from the soil and make them available to the plant

sugars produces by the plant through photosynthesis nourish the mycorrhizal fungi

LIfe Cycle of a Fungus

Asexual Reproduction of Fungi

making clones

spores grow and spread out

fungi can produce hige numbers of asexual spores, each germinate ot form a new fungus

spore-producing structures arise from haploid mycelia thay have undergone neither a heterokaryotic stage of meiosis

many fungi that reproduce sexually can also produce spores asexually

Sexual Reproduction of Fungi

makes variation

fuses nucliei of two different hyphae (heterokaryotic stage)

fuse to create a zygote (2n)

goes through meisosis

makes spores

Heterokaryotic Stage of Sexual Reproduction

The fusing of two nuclei from separate hyphae cells

shares and pass two pieces of DNA

• hours or centuries may pass before parental nuclei fuse to form a short lived diploid phase

• Zygotes undergo meiosis to produce haploid spores

Yeasts

single celled fungi, never make mycelium

only reproduce asexually cell division or budding (binary fission)

beer, bread

Molds

any rapidly growing fungus that reproces asexually by producing spores

form of asexual reproduction of fungi

Symbionts

live together with something

fungi can be symbiont

Parasites

living with something and absorbs food from their host at the expense of the host

fungi can be parasites