--- title: Microbes: bacteria and viruses, good and bad — a lesson of Mova's school · trees and pragmatics description: «Microbes: bacteria and viruses, good and bad», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Microbes are living things far too small to see; a thousand bacteria in a row would just about stretch across a pinhead. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / Microbes: bacteria and viruses, good a… # Microbes: bacteria and viruses, good and bad Lesson 63 of the biology course of Mova's primary school: 18 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/biology/63-microbes-bacteria-and-viruses/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/0/) — Microbes are living things far too small to see; a thousand bacteria in a row would just about stretch across a pinhead. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/1/) — Put a drop of pond water under the school microscope and a hidden zoo appears: wriggling, spinning, tiny creatures that were there all along. - [2](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/2/) — Most microbes are harmless or helpful: they make yoghurt and cheese, rot dead things, and trillions of them live in your gut helping to digest food. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/3/) — A few are germs that make us ill, and viruses are stranger still: much smaller than bacteria, they cannot do anything on their own and only copy themselves inside living cells. - [4](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/4/) — We fight bad germs with soap and water, vaccines that train the body, antibiotics for bacteria, and a fever that turns up the body's heat while it fights. - [5](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/5/) — Microbes are living things too small to see with the eye alone; a typical bacterium is about 1 to 2 thousandths of a millimetre long. - [6](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/6/) — The Dutch cloth merchant Antonie van Leeuwenhoek made tiny powerful lenses and was among the first to see microbes; in 1683 he described bacteria from scrapings of his own teeth. - [7](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/7/) — The human gut holds around 40 trillion bacteria, about as many as the body's own cells, and most of them are helpful. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/8/) — Yoghurt is milk changed by friendly bacteria, which eat the milk sugar and make lactic acid that thickens the milk and makes it tangy; «live cultures» on a pot means these friendly bacteria are still in it. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/9/) — Soap breaks up the greasy layer that germs cling to and running water rinses them away; washing for about 20 seconds gives it time to work; cold viruses spread on hands and on things people touch, like door handles. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/10/) — A cold is caused by a virus; a virus is much smaller than a bacterium and can only copy itself inside a living cell. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/11/) — Antibiotics kill bacteria or stop them growing but do nothing to viruses, so they do not help colds or flu, and using them when not needed helps bacteria become resistant; stopping a course of antibiotics early can leave the toughest bacteria alive to grow back. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/12/) — A vaccine shows the body a harmless copy or piece of a germ, so the immune system learns to recognise it and can fight the real germ fast; Edward Jenner made the first vaccine, against smallpox, in 1796. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/13/) — Smallpox, once one of the deadliest diseases, was wiped out from the whole world by vaccination, and this was declared in 1980: so many people were protected that the virus had nowhere left to spread. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/14/) — A fever means the body has turned up its thermostat to around 38 to 39 degrees instead of about 37, which helps the immune system fight germs. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/15/) — Plaque is a sticky film of bacteria on teeth; they feed on sugar and make acid that slowly dissolves the enamel and makes holes; a dentist's pink disclosing tablet colours the plaque you missed brushing. - [16](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/16/) — Some microbes live in extreme places, such as boiling hot springs; the bright rings of Grand Prismatic Spring in Yellowstone are mats of different microbes living at different temperatures, showing that life survives in places once thought impossible. - [17](https://md.mova.elamur.ai/free/en/corpora/school/biology/63-microbes-bacteria-and-viruses/17/) — Milk left out on a warm table goes sour because bacteria multiply fast in warmth and make acid; the fridge slows them down. - ← previous: [Fungi: mushrooms, mould and yeast](https://md.mova.elamur.ai/free/en/corpora/school/biology/62-fungi-mushrooms-mould-and-yeast/) - next →: [Cells, bones and muscles](https://md.mova.elamur.ai/free/en/corpora/school/biology/64-cells-bones-and-muscles/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)