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Fungi. Fungi are split into 3 groups known as moulds , mushrooms and yeasts . Most fungi are beneficial or useful to us like yeast (bread, beer and wine making), mushrooms (food), those that make antibiotics & those used in composting.
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Fungi • Fungi are split into 3 groups known as moulds, mushroomsand yeasts. • Most fungi are beneficialor useful to us like yeast (bread, beer and wine making), mushrooms (food), those that make antibiotics & those used in composting. • A few fungi are harmful or pathogenic. These include fungi that cause diseases such as athlete’s foot, thrush, ringworm, aspergillosis& pneumocystis pneumonia.
Structure of fungi • A mushroom Reproductive structure (cap of mushroom) hyphae mycelium
Structure of bread mould spores Sporangium (reproductive structure containing spores) Mycelium of hyphae Sporangiophore (reproductive hyphum)
Structures & function of fungi • Sporangium: a structure in which thousands of spores are produced and mature. • Spores: reproductive structures that are dispersed by the wind. They germinate and grow into a new fungus • Hyphae (spreading and absorbing): fine threads that grow throw the substrate or food. • Sporangiophore /reproducing hyphum: sporangia develop on the tip of these hyphae. These hold the reproductive structures above ground to aid spore dispersal
Structures & function of fungi (continued) • Mycelium: a network of hyphae • Reproductive structure/cap: in mushrooms and toadstools the cap contains the spores.
Fungal diseases (research 2 of these) • Thrush (Candidiasis) • Athlete’s foot • Ringworm (Dermatophytosis) • Pneumocystis pneumonia • Aspergillosis • Cryptococcus meningitis • Stachybotrys
Fungal Growth and Reproduction • Fungi grow by producing long threads called hyphae. • When food is in short supply fungi reproduce by asexual reproduction also known as spore formation. • This process is shown in the diagrams on the next slide:
When spores land on a suitable food supply they start to grow hyphae spores Spores put out hyphae Bread After a few days sporangia (spore heads) appear. Sporangia Mature sporangia burst and release huge numbers of spores into the air
The advantage of asexual reproduction over sexual reproduction is it is a quick process requiring only one parent cell, producing genetically identical offspring • The disadvantage of asexual reproduction over sexual reproduction is that there is no genetic variation and this
Sexual Reproduction in Fungi • Fungi can reproduce by sexual reproduction but this is quite rare. • The advantage of reproducing sexually is that this leads to variation which is very important if fungi want to survive.
How do fungi feed? • Fungi feed in a similar way to bacteria, by extracellular digestion. • Extracellular means outside the cell. • Digestion means to break down food into small soluble substances.
