THEDIFFERENCESBETWEENPLANTANDANIMALVIRUSES：植物和动物病毒之间差异课件.ppt

1、KINGDOM:FUNGIABBOTTS COLLEGEKINGDOM FUNGIABBOTTSTOPICS Structure Characteristics Diseases Neither plants nor animals E.g.mushrooms,moulds and yeast Estimated about 1 million speciesGENERAL CHARACTERISTICSFungi are found everywhere invisible to the naked eyeMostly free-living(live in soil,air and dea

2、d organic matter)Are heterotrophs -lack chlorophyllSaprotrophic feed on dead organismsParasitic get nourishment from a living host and cause diseases as a resultFORM SYMBIOTIC RELATIONSHIPS Some fungi live in symbiotic relationships with plants and animals The term symbiosis commonly describes close

3、 and often long-term interactions between different biological species.LICHEN An association of a fungi and algae The fungus supplies the alga with water and minerals The alga makes glucose that is absorbed by the fungusLichen thallus(cross-section)X 200.The algal cells are a lighter colour.They are

4、 surrounded by and held in place by fungal hyphae.MYCORRHIZAE Hyphae of a fungus which associate with the roots of many types of plants Fungus gets food from the plant Plant gets an increased surface area for water absorptionMOST FUNGI ARE USEFUL They are primary decomposers of dead organic matter C

5、lean the environment Nutrients are re-cycled and returned to the soilFUNGI:REPRODUCTION Asexually by means of spores Sexually when conditions are unfavourable by means of zygospores By budding or binary fission(yeast)ASEXUAL REPRODUCTION BY SPORESSpores are the units of asexual reproduction,because

6、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.Sexual reproduction by zygosporesA large multinucleate spore formed by union of similar gametes,as in algae or fungi.buddingBINARY FISSION IN YEAS

7、TSTRUCTURE 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 hyphaeHYPHAEHYPHA Is a multi branched tubular cell filled with cytoplasm The tube can be continuous(aseptate)or

8、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)SPORANGIA When a fungus reproduces asexually it forms sporangia(spore producing bodies)HARMFUL FUNGI Pathogenic fungi are parasites causi

9、ng 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 plantsFUNGAL DISEASES Thrush Rusts Ringworm Athletes footCANDIDIASIS/THRUSH Also called a candida infection or yeast infection Caused by Candida albicans(a yeast/fungus)Affect

10、s 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 babiesFACTORS WHICH ENCOURAGE GROWTH Taking antibiotics red

11、uces 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 areasMANAGEMENT OF THRUSH Oral thrush antifungal mouthwash Vaginal yeast infections antifungal medication e.g.creamsATHLETES 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 powderPAGE 23THE END