Class 8 microorganisms at 1pm 16th april

Class 8 microorganisms at 1pm 16th april

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  MICROORGANISMS FRIEND AND FOE
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  W H ATA R E M I C R O O R G A N I S M S ? A living organism that is very minute to be seen by the naked eye , especially a single celled organism , such as a bacterium is called a microorganism. They are classified into five major groups- bacteria, virus, protozoa, algae and fungi.
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  CLASSIFICATION OF MICROORGANISMS •BACTERIA - These are unicellular prokaryotic microorganisms. • VIRUS – These are also unicellular and are considered to be on the borderline between living and non-living entities. • PROTOZOA - These are unicellular microorganisms. • FUNGI – These can be both unicellular and multicellular.
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  BACTERIA Bacteria are singlecelled and very small organisms. They are prokaryotic microorganism which means they do not have nucleus. They are among the simplest forms of life known, and, hence shows the characteristics of both plants and animals. It was discovered in 1676 by Anton van Leeuwenhoek. Some species of bacteria are parasites which attack plants or animals. Some of them are saprophytes which grow on dead remains or products of plant and animal life. Parasitic bacteria are responsible for someof the diseases of plants and animals, whereas, the saprophytic kinds may be beneficial in one way or the other. They are classified into 5 groups according to their basic shapes: spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrous) or corkscrew (spirochaetes) .
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  VIRUSES Viruses are microscopicinfectious agents that can only replicate only inside a host cell. From a biological perspective, they cannot be classified either as living nor non-living. This is due to the fact that they possess certain defining characteristic feature of living and non-living entities. They are inactive when they are present outside the host cells but become active within the host cells. Viruses cause several infections and reproduce within the host cells by using the enzymes and raw materials.
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  PROTOZOA They are singlecelled organisms. They come in many different shapes and sizes ranging from amoeba which can change its shape to Paramecium with its fixed shape and complex structure. They live in a wide variety of moist habitats including fresh water, marine environments and the soil. They cause diseases in both plants and animals. They are motile and can move by • Cilia – tiny hair like structures that cover the outside of the microbe. • Flagella – long thread like structures that extend from the cell surface. The flagella move in a whip-like motion that produces waves that propel the microbe around. • Amoeboid movement- the organism moves by sending out pseudopodia, which are also known as false feet as in amoeba.
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  FUNGI They are plantlike organisms that do no contain chlorophyll . They may be unicellular (yeast) or multicellular ( bread mould) and are found in warm and moist places. They can be heterotrophic, saprophytic or parasitic in nutrition.  Almost all the fungi have a filamentous structure except the yeast cells.  They consist of long thread like structures known as hypae.  They reproduce by means of spores.  Some are parasitic and can infect the host.  Some of them are edible like mushroom and yeast which is used in food industry,
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  ALGAE Algae are simpleplant-like organisma which are usually aquatic in nature. They contain a cell wall and chlorophyll and can make their own food by photosynthesis. They can be unicellular or multicellular. They lack a well-defined body, so, structures like roots, stems or leaves are absent. They are found where there is adequate moisture. Algae are free living , although some can form a symbiotic relationship with other organisms like in lichens. Some of them are spirogyra, diatoms and duckweed.
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  USES OF MICROORGANISMS •Lactobacillus a type of bacteria is used to form curd form milk. • Rhizobium present in the roots of pulse plants fix nitrogen from air and supply nitrogen compounds to the pulse (leguminous) plants. • Micro-organism are also used in winemaking, baking, pickling and other food making processes. • Alcoholic fermentation by yeast is widely used in the preparation of wine and bread. • Microbes are used to reduce pollution. For example: decomposers such as bacteria and fungi break down dead bodies and excreta to form inorganic compounds which can be absorbed by plants. • Microbes also play an important role in the preparation of medicines. Antibiotics are chemicals produced by micro-organisms to kill bacteria. Penicillin is an antibiotic made from Penicillium. • Bacteria present in our intestines helps in proper digestion and release Vitwamin B which is absorbed by the intestines. • Many vaccines are prepared from microorganisms. These are given to children to protect them from diseases. • Certain microbes are also used in the biological treatment of sewage and industrial effluents.
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  HARMFUL EFFECTS OFMICROORGANISMS • Microorganisms cause diseases in humans, animals as well as plants. • Food poisoning is also caused by the microorganisms that spoils our food by producing some toxic substances . HUMAN DISEASE CAUSATIVE ORGANISM MODE OF TRANSMISSON GENERAL PREVENTIWVE MEASURES 1.Covid-19 virus Droplets generated when an infected person coughs, sneezes or exhales Stay home Keep a safe distance Wash hands often Cover your cough 2. Measles 3. Chickenpox 4. Polio 5. Tuberculosis Virus Virus Virus Bacteria Air Air/contact Air/water Air 1. The patient should be kept in complete isolation. 2. The personal belonging of the patient should be kept away from others. 3. Vaccination should be done at a suitable age.
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  HUMAN DISEASES CAUSATIV E ORGANIS M MODE OF TRANSMISSION PREVENTIVE MEASURES 6.Cholera 7. Typhoid Bacteria Bacteria Water/food water 1. Maintain personal hygiene and good sanitary habits. 2. Eat properly cooked food. 3. Drink clean and boiled water. 4. Vaccination should be done 8. Hepatitis B Virus Water 1. Drink clean and boiled water. 2. Vaccination 9. Malaria 10. Dengue Protozoan Virus Mosquito Mosquito 1. Do not allow to collect surroundings. 2. Spray insecticides in homes to kill mosquitoes.
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  DISEASE CAUSING MICROORGANISMSIN ANIMALS AND PLANTS ANIMAL NAME NAME OF THE DISEASE CAUSATIVE ORGANISM 1. CATTLE 2. CATTLE 3. POULTRY BIRDS FOOT AND MOUTH DISEASE ANTHRAX ASPERGILLOSIS VIRUS BACTERIA FUNGUS PLANT DISEASE 1. WHEAT 2. CITRUS TREES 3. BHINDI RUST OF WHEAT CITRUS CANKER YELLOW VEIN MOSAIC FUNGUS BACTERIA VIRUS
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  PRESERVATION OF FOOD 1.By Sun-drying 2. By heating 3. By cooling or refrigeration 4. By deep – freezing 5. By adding common salt 6. By adding sugar 7. By adding oil or vinegar 8. By using special chemicals as preservatives ( Sodium benzoate and citric acid) 9. By Pasteurization (heating milk to about 70degrees centigrade and cooling very quickly) 10. By Packing in Air-tight packets
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  NITROGEN CYCLE