Presentation on theme: "Mushrooms, mould, and mildew Fungi in action"— Presentation transcript:
1 Mushrooms, mould, and mildew Fungi in action Kingdom FungiMushrooms, mould, and mildewFungi in action
2 Characteristics of Fungi In partners or as a group – what characteristics define a fungus (pl)?If you said:EukaryoticHeterotrophic, but do not have an internal digestive system (have external digestion)Non vascular (no root system)Reproduce sexually and asexuallyYou’d be right!
3 Wait...Fungi aren’t plants? Have a root systemAutotrophsCell wall composed of celluloseFungiNon-vascular systemHeterotophicCell wall is composed of chitin
4 Structure of Fungi Some fungi are single-celled They are called yeasts Valuable economically – can you think why?
5 Structure of Fungi Most fungi are multi-cellular Body of a fungi generally occurs below groundBody = mycelium = a branching, mesh-like network of hyphaeWhere do you think most of the body of a fungus occurs? Above ground or below ground
6 Structure of Fungi cont. An individual filament is called a hypha (hyphae (pl))One long continuous multicellular structureHyphae have a structure unlike plant or animal cells; consist of long tubes of cytoplasm containing many nuclei; cytoplasm contained by a cell wall that consists of chitin; tubes separated into cell-like compartments by cell walls called speta (septum) -
7 Structure of Fungi cont. So what is a ‘mushroom’?It is the spore producing reproductive structure of a fungus, which is called the fruiting bodyMade of hyphae that are densely packed togetherHyphae have a structure unlike plant or animal cells; consist of long tubes of cytoplasm containing many nuclei; cytoplasm contained by a cell wall that consists of chitin; tubes separated into cell-like compartments by cell walls called speta (septum) -
8 Fungal Nutrition Fungi release enzymes into their surrounding Enzymes break down the food externallyFungi then absorb the nutrients that have been released by the enzymes through its cell membraneOne way of classifying fungi is through the four different ways that they obtain nutrientsHyphae have a structure unlike plant or animal cells; consist of long tubes of cytoplasm containing many nuclei; cytoplasm contained by a cell wall that consists of chitin; tubes separated into cell-like compartments by cell walls called speta (septum) -
9 Fungal Nutrition Parasitic Fungi absorbs nutrients from the living cells of a host organismResults in death of the hostIn this case, fungi generally lives inside the host organism
10 Fungal Nutrition Predatory Soil fungi whose mycelia have specialized structures for trapping preyNematode caught in constricting rings of hyphae
11 Fungal Nutrition Mutualistic Fungi that have partnerships with other organisms (e.g. Plants, protists or animals)Both organisms involved in the partnership benefit from the relationshipAnother example = relationship many fungi have with plants. In this case, mycelia covers plant roots – increase surface area of roots , allowing plants to take in more nutrients and provide fungus with sugar (food)Eg. Lichen – an organism that results from a mutualistic relationship b/w a fungus and a photosynthetic plant or alga
12 Fungal Nutrition Saprobial Fungi that feed on dead or decaying organic matteri.e. They are decomposersVery important in nutrient recycling
13 Learning Check 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?
14 Fungal Classification 5 Major PhlyaPhylum Chytridiomycota (chytrids)Phlyum Zygomycota (zygomycetes)Phylum DeuteromycotaPhylum Ascomycota (ascomycetes)Phylum Basidiomycota (basidiomycetes)Based on differences in reproduction and the structure of the fruiting body they produce
15 Fungi Imperfecti (Deuteromycota) Not known to reproduce sexuallyGenerally types of mouldsE.g. Penicillium mould; mould in blue cheese
16 Chytrids (P. Chytridomycota) Mostly unicellularAquatic species (marine or freshwater)Spores have flagella (motile)Parasitic or saprophytes
17 Zygospore Fungi (P. Zygomycota) Multicellular and mostly terrestrial (soil)Include familiar bread and fruit mouldsGenerally reproduce asexually
18 Zygospore Fungi (P. Zygomycota) Reproduce sexually in unfavourable conditions to produce zygosporesDiploid structure (2n) that develops after two haploid (n) hyphae of opposite types combine their nuclei. Thick wall develops around nuclei to protect it.
19 Sac Fungi(P. Ascomycota) Largest fungi groupDevelop small finger-like sacs called asci (contain spores) during sexual reproduction (similar to creation of zygospores)Saprophyte and parasitesIncludes yeasts, which reproduce by buddingSexual reproduction involves the fusion of two mating types to form spore-bearing asci
20 Club Fungi (P. Basidiomycota) Includes ‘mushrooms’, puffballs, and stinkhornsMost are decomposers, some form symbiotic (mutualistic) relationship with plantsE.g. lichenSexual reproduction involves the fusion of two mating types to form spore-bearing asci
21 Club Fungi (P. Basidiomycota) Fruiting bodies release spores called basidiospores from basidia (club-shaped hypha)
22 ReproductionAsexualBudding – a smaller cell develops while attached to a parent cell. Eventually, small cell is pinched off of parent cell to produce a new individual
23 ReproductionAsexualFragmentation – a piece of mycelium breaks and forms a new individualSpore productionSexual reproduction - also involves spore production and often the creation of a fruiting body above groundFig3.21 (hand-out)
24 The Importance of Fungi Fungi are:Decomposers – one of the most important groups for recycling materials along with BacterisForm symbiotic relationships – esp. with plants. Without these relationships plant growth and productivity would be reducedFood source (e.g. Blue cheese, mushrooms) and used in food production (bread, beer)
25 The Importance of Fungi 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
26 The Importance of 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)
27 Meet the worlds largest organism Honey mushrooms – give an inkling of what is below.