Fungi: a large & successful

group100 000 species

Fungi range in size:

unicellular yeasts

large puffball

20-60 cm

Fungi occupy a range of habitats:

aquatic

Marine fungi

terrestrial

New Glowing Fungi Species

Found in Brazil [October, 2010]

terrestrialSearching for

truffles

$4,000 per kilogram

The female pig becomes excited when she sniffs a chemical that is

similar to the male swine sex attractant.

Fungi include:moulds – grow on: damp organic material (e.g.

bread, leather & decaying vegetation and dead fish)

Fungi include:unicellular yeast – abundant on sugary

surfaces of ripe fruit

parasites

Rust fungus

About 30% of the 100,000 known species of fungi are parasites, mostly on or in plants.

Parasitic brackets

Only about 50 fungal species are known to parasitise humans

and other animals, but their damage can be disproportionate to

their taxonomic diversity.

ringworm

The yeast Candida causes Thrush

FUNGUS

General Characteristics of Fungi

1. Heterotrophic nutrition: lack chlorophyll and so are non-

photosynthetic can be:

Parasites Saprotrophs Mutualists

Mycorrhiza

Plant growth without mycorrhizae is often

stunted.

nutrition is absorptive

3. Nutrients are

absorbed from all

over the hyphae.

1. Extracellular

enzymes from

growing tips.

2. Digestion takes place outside the body.

2. Rigid cell walls containing chitin

Chitin: a nitrogen-containing polysaccharide, very similar in structure to cellulose

Chitin: like cellulose has a high tensile strength and

so:

gives shape to

the hyphae

prevents

osmotic

bursting of cells

3. Body is usually a mycelium

mycelium is a network of fine tubular filaments called hyphae

A hypha grows out of a germinating spore

Mycelium

What is a ‘hypha’?

a cylindrical, branching

filament composed of a

tubular cell wall filled with

cytoplasm and organelles

A hypha is:

(lacks septa)

Mycelium may be:

i) septate (have cross-walls) e.g. Penicillium, or

ii) aseptate (no cross-walls present; are coenocytic) e.g. Mucor (fig. 2).

4. Store glycogennot starch

  Spores being dispersed

Spores inside sporangium

Arial hyphae

Branching hyphae

Hyphae dividing at tip

5. Method of Reproduction :

Asexual reproduction

Spore production

Sexual reproduction

Conjugation

- filaments of different

mating types fuse

What is a ‘spore’?

A reproductive cell that is capable of growing into a new individual by mitosis alone

6. Non-motilecells never

possess flagella

What is a fungus?

A eukaryotic, heterotrophic organism devoid of chlorophyll that obtains its

nutrients by absorption, and reproduces by spores

Fairy ring of mushrooms

THE END