Fungi SBI3U(G) Past Paper Sept 2021 PDF

 Fungi SBI3U(G) Introduction to Fungi Fantastic Fungi Kingdom of the Forest ◆ Eukaryotic heterotrophic, absorptive organism ◆ Range in size from unicellular yeasts to multicellular mushrooms ◆ Once thought to be plants, but actually have very little in...

 Fungi SBI3U(G) Introduction to Fungi Fantastic Fungi Kingdom of the Forest ◆ Eukaryotic heterotrophic, absorptive organism ◆ Range in size from unicellular yeasts to multicellular mushrooms ◆ Once thought to be plants, but actually have very little in common with plants – More closely related to animals  Benefits ◆ Important role in ecosystems: – Decomposers – Symbiotic relationships with plants (allow plants to obtain nutrients) – Nutrient cycling ◆ Important role with humans: – Food ◆ mushrooms, truffles, beer and wine production, etc – Drug production ◆ Cyclosporine (anti-rejection drug for organ transplant patients)  Harm ◆ Cause animal and plant diseases ◆ Destroy harvests ◆ Rot wood and buildings  How are fungi similar to plants? ◆ Sessile (stationary) ◆ Multicellular ◆ Grow from ground ◆ have ‘stem’ How are fungi different from plants? ◆ Not photosynthetic ◆ Heterotrophic (can’t produce their own food) ◆ Don’t have true roots ◆ Cell wall contains chitin (plants have cellulose) – Chitin is also used by arthropods (such as bugs) for their exoskeleton  Structure of Fungi ◆ The bits we see… – Above ground parts are reproductive parts only – Their purpose is to spread spores  Structure of Fungi ◆ Their body is called a mycelium and consists of an extensive network of microscopic threadlike filaments called hyphae The Bits We Don’t See…  Structure of Fungi ◆ When fungal cells divide, the cell wall doesn’t completely separate the new cells – hyphae end up being long tubes of cytoplasm with many nuclei.  Fungal Reproduction ◆ Most parts of a fungus are haploid (one copy of each chromosome). – Humans are mostly diploid (two of each chromosome) ◆ On the next slide, we will look at the life cycle of basidiomycete  2. Two haploid hyphae can fuse to produce 3. Produce a complete dikaryotic cells (2 haploid nuclei) dikaryotic fungal mycelium The mature 4. mycelium produces a 1. fruiting body Haploid spores (eg. a germinate to 5. mushroom) form haploid Within the fruiting hyphae body, the haploid nuclei fuse, forming a diploid zygote 6. The zygote then produces 4 haploid spores by meiosis.  Fungal Reproduction ◆ The haploid spores are dispersed by wind or water to start the cycle all over again. ◆ A single large mushroom can release 100 million spores in an hour. – You are breathing them in right now!  Fungal Nutrition ◆ Fungi secrete digestive enzymes onto organic matter and absorb the products as food – These feeding habits require an enormous surface area extending throughout the material they are growing in ◆ Decomposers: – Saprobes are decomposers. These fungi absorb nutrients from dead organisms, recycling nutrients in ecosystems.  Symbiotic Relationships ◆ Parasitic: – Absorb nutrients from the living cells of a host organism. – Ex. athletes’ foot ◆ Predatory: – Some soil fungi have mycelia that can trap tiny nematode worms.  Symbiotic Relationships ◆ Mutualistic: – Mycorrhiza form symbiotic partnerships with plant roots. They help the plants absorb materials from soil and in return get sugar from the plant.  Symbiotic Relationships ◆ Mutualistic: – Lichens ◆ Combination of fungi and cyanobacteria or green algae. ◆ The fungus gets sugars from the algae and the algae gets a weather resistant home in the sun ◆ Relationship allows it to survive in harsh environments  Conditions Needed for Growth ◆ Continuous moisture ◆ Continuous food supply ◆ Ideal temperature Major Fungal Phyla  1) Ascomycota (Sac Fungi) ◆ Named after the small finger-like sacs (asci) in which their spores develop  Example ◆ Yeast ◆ ◆ Cordyceps – Genus of Ascomycota fungi CD e w https://www.youtube.com/watch? v=XuKjBIBBAL8 2) Basidiomycota (Club Fungi) ◆ Includes mushrooms, puffballs, etc ◆ Release basidiospores from club-shaped basidia in the fruiting body ◆ Form symbiotic relationships with plants ◆ Decomposers  3) Chytridomycota ◆ Mostly unicellular and aquatic ◆ Only fungi with swimming spores – Flagellated ◆ Important decomposers of cellulose (wood) and keratin (hair and nails)  4) Glomeromycota ◆ All form symbiotic relationships with plant roots – Ex. mycorrhyzae  5) Zygomycota ◆ Bread and fruit mould ◆ Most are soil fungi ◆ Many are parasites of insects  https://www.youtube.com/watch?v=dj9m7Oc36wM Bozeman 9 min https://www.youtube.com/watch?v=b5rluxtABGA cool hand drawn tutorial (6 min) http://www.bbc.co.uk/programmes/p0038s7f BBC fungal timelaps ( 2min) https://www.youtube.com/watch?v=XuKjBIBBAL8 BBC cordyceps http://thekidshouldseethis.com/post/10240509548 (5 min spore acceleration) https://www.youtube.com/watch?v=U5uuOzi7D8Q lung infection (3 min) https://www.youtube.com/watch?v=nPN--7j5mdI Fantastic Fungi time lapse (3.5 min)  Homework 1. Complete Fungi Worksheet