KINGDOM : FUNGI ABBOTTS COLLEGE KINGDOM FUNGI ABBOTTS

TOPICS Structure Characteristics Diseases Structure Characteristics Diseases

Neither plants nor animals E.g. mushrooms, moulds and yeast Estimated about 1 million species Neither plants nor animals E.g. mushrooms, moulds and yeast Estimated about 1 million species

GENERAL CHARACTERISTICS  Fungi are found everywhere – invisible to the naked eye  Mostly free-living (live in soil, air and dead organic matter)  Are heterotrophs - lack chlorophyll  Saprotrophic – feed on dead organisms  Parasitic – get nourishment from a living host and cause diseases as a result  Fungi are found everywhere – invisible to the naked eye  Mostly free-living (live in soil, air and dead organic matter)  Are heterotrophs - lack chlorophyll  Saprotrophic – feed on dead organisms  Parasitic – get nourishment from a living host and cause diseases as a result

FORM SYMBIOTIC RELATIONSHIPS Some fungi live in symbiotic relationships with plants and animals The term symbiosis commonly describes close and often long-term interactions between different biological species.species Some fungi live in symbiotic relationships with plants and animals The term symbiosis commonly describes close and often long-term interactions between different biological species.species

LICHEN

Lichen thallus (cross- section) X 200. The algal cells are a lighter colour. They are surrounded by and held in place by fungal hyphae. Lichen thallus (cross- section) X 200. The algal cells are a lighter colour. They are surrounded by and held in place by fungal hyphae.

MYCORRHIZAE

MOST FUNGI ARE USEFUL

FUNGI: REPRODUCTION Asexually by means of spores Sexually when conditions are unfavourable by means of zygospores By budding or binary fission (yeast) Asexually by means of spores Sexually when conditions are unfavourable by means of zygospores By budding or binary fission (yeast)

ASEXUAL REPRODUCTION BY SPORES Spores are the units of asexual reproduction, because a single spore develops into a new organism. By contrast, gametes are the units of sexual reproduction, as two gametes need to fuse to create a new organism.asexual reproductionsexual reproduction Spores are the units of asexual reproduction, because a single spore develops into a new organism. By contrast, gametes are the units of sexual reproduction, as two gametes need to fuse to create a new organism.asexual reproductionsexual reproduction

Sexual reproduction by zygospores A large multinucleate spore formed by union of similar gametes, as in algae or fungi.

budding BINARY FISSION IN YEAST

STRUCTURE OF FUNGI Most are multicellular eukaryotes Some are unicellular examples (yeast) Cells walls contain chitin and glucan Multicellular fungi consist of fine branched threads called hyphae Most are multicellular eukaryotes Some are unicellular examples (yeast) Cells walls contain chitin and glucan Multicellular fungi consist of fine branched threads called hyphae HYPHAE

HYPHA Is a multi branched tubular cell filled with cytoplasm The tube can be continuous (aseptate) or septate (divided into compartments) Is a multi branched tubular cell filled with cytoplasm The tube can be continuous (aseptate) or septate (divided into compartments)

MYCELIUM Hyphae branch repeatedly to form a network called the mycelium Which makes up the thallus (vegetative part of the fungus) Hyphae branch repeatedly to form a network called the mycelium Which makes up the thallus (vegetative part of the fungus)

SPORANGIA When a fungus reproduces asexually it forms sporangia (spore producing bodies)

HARMFUL FUNGI Pathogenic fungi are parasites causing ill health in plants and animals Get their nourishment from a living host E.g. thrush and athletes foot in man E.g. rust in plants Pathogenic fungi are parasites causing ill health in plants and animals Get their nourishment from a living host E.g. thrush and athletes foot in man E.g. rust in plants

FUNGAL DISEASES

CANDIDIASIS/THRUSH Also called a candida infection or yeast infection Caused by Candida albicans (a yeast /fungus) Affects the mucous membranes Can occur harmlessly in the body Healthy immune system: friendly bacteria keep them in check in the intestine Under certain conditions they grow too fast and cause an infection Common in the mouth, vagina or GI tract in babies Also called a candida infection or yeast infection Caused by Candida albicans (a yeast /fungus) Affects the mucous membranes Can occur harmlessly in the body Healthy immune system: friendly bacteria keep them in check in the intestine Under certain conditions they grow too fast and cause an infection Common in the mouth, vagina or GI tract in babies

FACTORS WHICH ENCOURAGE GROWTH Taking antibiotics [reduces the number of friendly bacteria] AIDS and cancer weakens the immune system Stress, poor diet, lack of sleep Tight clothing promotes moisture build up in genital areas Taking antibiotics [reduces the number of friendly bacteria] AIDS and cancer weakens the immune system Stress, poor diet, lack of sleep Tight clothing promotes moisture build up in genital areas

MANAGEMENT OF THRUSH

ATHLETES FOOT Caused by a fungus called Tinea Grows in damp places Quite common Skin flakes and cracks between the toes Fungus feeds on keratin [protein found in skin cells] Treated with antifungal powder Caused by a fungus called Tinea Grows in damp places Quite common Skin flakes and cracks between the toes Fungus feeds on keratin [protein found in skin cells] Treated with antifungal powder PAGE 23

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