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What are germs? - Bacteria, fungi, virus are microbes. - Some microbes are useful for making bread, cheese, wine. - Germs: are the microbes that cause disease. - Not all diseases are caused by microbes. * Bacteria - Bacteria are cells that are big enough to be seen under a light microscope. - Bacteria are found everywhere: - in the air, in the food, in the water, inside living organisms. - Some are useful and others are harmful that cause diseases such as pneumonia, tuberculosis, scarlet fever. - Bacterial cell: has a cell wall, cell membrane, a loop of DNA. Cell Wall Cell Membrane Loop of DNA *Bacterial growth: - Bacteria can be grown in sterile conditions in the laboratory. - A colony of bacteria starts with just 1 cell. - It divides into 2 cells, then the 2 divide into 4, then the 4 divide in to 8, then the 8 divide into 16 and so on.
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