Presentation on theme: "Mushrooms, mould, and mildew Fungi in action. In partners or as a group – what characteristics define a fungus (pl)? If you said: Eukaryotic Heterotrophic,"— Presentation transcript:
Mushrooms, mould, and mildew Fungi in action
In partners or as a group – what characteristics define a fungus (pl)? If you said: Eukaryotic Heterotrophic, but do not have an internal digestive system (have external digestion) Non vascular (no root system) Reproduce sexually and asexually You’d be right!
Plants Have a root system Autotrophs Cell wall composed of cellulose Fungi Non-vascular system Heterotophic Cell wall is composed of chitin
Some fungi are single-celled They are called yeasts Valuable economically – can you think why?
Most fungi are multi-cellular Body of a fungi generally occurs below ground Body = mycelium = a branching, mesh-like network of hyphae
An individual filament is called a hypha (hyphae (pl)) One long continuous multicellular structure
So what is a ‘mushroom’? It is the spore producing reproductive structure of a fungus, which is called the fruiting body Made of hyphae that are densely packed together
Fungi release enzymes into their surrounding Enzymes break down the food externally Fungi then absorb the nutrients that have been released by the enzymes through its cell membrane One way of classifying fungi is through the four different ways that they obtain nutrients
1.Parasitic Fungi absorbs nutrients from the living cells of a host organism Results in death of the host
2.Predatory Soil fungi whose mycelia have specialized structures for trapping prey
3.Mutualistic Fungi that have partnerships with other organisms (e.g. Plants, protists or animals) Both organisms involved in the partnership benefit from the relationship
4.Saprobial Fungi that feed on dead or decaying organic matter i.e. They are decomposers Very important in nutrient recycling
What is mycelium and where is it found? When you see a mushroom growing from a dead log, which part of the fungus are you observing?
5 Major Phlya Phylum Chytridiomycota (chytrids) Phlyum Zygomycota (zygomycetes) Phylum Deuteromycota Phylum Ascomycota (ascomycetes) Phylum Basidiomycota (basidiomycetes) Based on differences in reproduction and the structure of the fruiting body they produce
Not known to reproduce sexually Generally types of moulds E.g. Penicillium mould; mould in blue cheese
Mostly unicellular Aquatic species (marine or freshwater) Spores have flagella (motile) Parasitic or saprophytes
Multicellular and mostly terrestrial (soil) Include familiar bread and fruit moulds Generally reproduce asexually
Reproduce sexually in unfavourable conditions to produce zygospores Diploid structure (2n) that develops after two haploid (n) hyphae of opposite types combine their nuclei. Thick wall develops around nuclei to protect it.
Largest fungi group Develop small finger-like sacs called asci (contain spores) during sexual reproduction (similar to creation of zygospores) Saprophyte and parasites Includes yeasts, which reproduce by budding
Includes ‘mushrooms’, puffballs, and stinkhorns Most are decomposers, some form symbiotic (mutualistic) relationship with plants E.g. lichen
Fruiting bodies release spores called basidiospores from basidia (club-shaped hypha)
Asexual Budding – a smaller cell develops while attached to a parent cell. Eventually, small cell is pinched off of parent cell to produce a new individual
Asexual Fragmentation – a piece of mycelium breaks and forms a new individual Spore production Sexual reproduction - also involves spore production and often the creation of a fruiting body above ground Fig3.21 (hand-out)
Fungi are: Decomposers – one of the most important groups for recycling materials along with Bacteris Form symbiotic relationships – esp. with plants. Without these relationships plant growth and productivity would be reduced Food source (e.g. Blue cheese, mushrooms) and used in food production (bread, beer)
Fungi are: Sources of antibiotics (medicine) (e.g. Penicillin). The discovery of antibiotics revolutionized health care worldwide. Biocontrol – use fungi that target insects to control crop pests (e.g. Chinese caterpillar fungus; control of California potato beetles). This is cheaper and less damaging to the environment than using chemical pesticides
Fungi Cause animal and plant disease (e.g. Every year 10 – 50% of world’s fruit harvest is destroyed by fungi!) (e.g. Athlete’s foot, ringworm) Food spoilage (mould)
http://www.scientificamerican.com/article.cfm?id=strange-but-true- largest-organism-is-fungus Honey mushrooms – give an inkling of what is below.