Post on 19-Aug-2015
Fungi: a large & successful
group100 000 species
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)
parasites
Rust fungus
About 30% of the 100,000 known species of fungi are parasites, mostly on or in plants.
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
General Characteristics of Fungi
1. Heterotrophic nutrition: lack chlorophyll and so are non-
photosynthetic can be:
Parasites Saprotrophs Mutualists
Mycorrhiza
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
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
What is a fungus?
A eukaryotic, heterotrophic organism devoid of chlorophyll that obtains its
nutrients by absorption, and reproduces by spores