A hidden world. 8Ca(1) I CAN... Name Class Date. 1 Complete the table of life processes. being able to move all or a part of itself

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1 Ca(1) A hidden world Name Class Date 1 Complete the table of life processes. Life process Meaning being able to move all or a part of itself producing more living things like itself sensing and reacting to things around it increasing in size Ca using a chemical reaction to release energy getting rid of waste materials that it makes needing food 2 a Look at the organisms in the box. Circle three that are microbes. bacteria cats daffodils dirt dust mice oak trees pollen grains viruses yeasts b Write down the three microbes that you circled in order of size, starting with the smallest. recall the seven life processes recognise different kinds of microbes. Exploring Science edition 105 Pearson Education Limited 200

2 Types of Microbe Cut and paste these boxes to group the facts together. Bacteria These are the smallest type of microbe. They are very simple and do not really have cells. Most of these are formed from thin, threads called hyphae. Fungi They reproduce by growing and then splitting in two. They are easy to see because they have big reproductive structures. They make dust-like spores that spread in the air. Viruses These are tiny, single cells. The cells are different from ours because they do not have a nucleus. They need to be in the cells of other living things to reproduce, this is why they cause diseases. Use the names of the types of microbe to finish off the sentences......are used to make bread and beer. Food poisoning is usually caused by cause illnesses such as flu, colds and measles.... are used to make cheese and yoghurt. Mould on bread is caused by are the smallest.... are usually made up of branched threads.... can only reproduce inside the cells of animals or plants.

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5 Ca(3) Microbe quest Name Class Date 1 a From the following box, circle the things that are micro-organisms. elephants yeasts humans earthworms daffodils bacteria viruses b Write down the list again, in order of size. Start with the biggest one. 1 (biggest) (smallest) Ca c Name one thing that elephants and bacteria can both do. 2 a Here are some drawings of different bacteria. Use the key to identify which is which. Write down the correct name underneath each picture (you do not need to remember the names). i ii iii iv Is each cell ball-shaped? Does the cell have more than one tail? No Yes Are the cells linked together in groups? No Yes No Yes Is the cell comma shaped? No Yes Spirillum Vibrio Salmonella Coccus Diplococcus Are there more than two bacteria in each group? No Yes Are the bacteria arranged as a chain? No Yes Staphylococcus Streptococcus b Draw a picture of what you think a Vibrio looks like. recall some differences between microbes use a key to identify organisms. Exploring Science edition 107 Pearson Education Limited 200

6 Ca(4) Which microbe? 1 The pictures show the outsides of a virus, a bacterium and a yeast cell. Which one is which? a b Ca c Drawings not to scale 2 Look at the pictures in question 1 again. a In real life, which one is the smallest? b In real life, which one is the biggest? Read the passage below and then answer the questions that follow. Very small living things are called microbes or micro-organisms; organisms because they are living things, micro- because they are very small. All living things should be able to carry out the seven life processes. However, viruses are a bit of an exception to this rule and some scientists do not think that they are really living. Of the seven life processes, they can only reproduce and even then they cannot do this on their own they need to be inside another living cell. People often think of viruses as microbes because they are very small and, like all living things, contain genes (the instructions for life our genes are in the nuclei of our cells). 3 a What is the proper name for a living thing? b What is the other name for microbe? c What piece of equipment do you need to use to see micro-organisms? d List the seven life processes. e Which of these life processes can viruses not do? f Which of these life processes can viruses do when inside another living cell? g If they are not really living, why do people tend to call viruses micro-organisms? recall what a microbe is recall some differences between microbes. Exploring Science edition 10 Pearson Education Limited 200

7 Ca(6) Microbial world Microbes come in many shapes and sizes. The pictures below show the outsides of some microbes with a scale given for each. 1 µm (micrometre) = mm, 1 nm (nanometre) = mm. 1 m 1 m Escherichia coli 1 nm 1 mm Vibrio cholerae Thiomargarita namibiensis Ca 1 m 50 nm Yeast 200 nm Adenovirus Retrovirus Ebola virus 1 a Design a table to show the lengths (or diameters if they are round) of each microbe. Put the organisms in order starting with the longest. b What do you think is unusual about Thiomargarita namibiensis? 2 a Copy these drawings and fill in the missing labels. b What feature do some bacteria have that allows them to move? c Why is it not really correct to call a virus a microbe? d What is the name given to the process that viruses use to reproduce? (Hint: It s an anagram of PELICAN RIOT.) present data as a table interpret drawings at different scales describe the basic structure of different microbes. Exploring Science edition 111 Pearson Education Limited 200

8 Cb(1) Microbes in action Name Class Date 1 Here is a list of foods. Circle the ones that are made using microbes. biscuits bread Cb celery cheese chicken sausages tomato yoghurt 2 What microbe is used to brew beer? 3 a What gas from the air do the microbes in bread dough use? b What gas causes bread dough to rise? 4 Microbes grow best in certain conditions. Circle these conditions. cold temperature damp dry little sugar lots of sugar warm temperature recall some uses of microbes describe the conditions in which microbes grow well. Exploring Science edition 113 Pearson Education Limited 200

9 Cb(2) Rising dough 1 Which temperature is best for dough to rise? You are going to investigate how temperature affects the rising of bread dough. Yeast is a microbe that is added to bread dough. When the yeast cells respire they produce carbon dioxide, which makes the dough rise. Respiration is a chemical reaction that happens in all living cells including yeast cells. Prediction 1 a Do you think the dough will rise furthest in cold or warm conditions? b Why do you think this? Cb Apparatus three measuring cylinders bread flour dried yeast large beaker stirring rod sugar tablespoon thermometer water Method 100 cm 3 cold 20 cm 3 0 Do not eat any dough. 100 cm cm 3 cool warm 20 cm 3 20 cm A Measure out 5 g of sugar, 3.5 g of yeast and 100 g of bread flour. Add them all to a large beaker. B Now measure out 65 cm 3 of water. C Pour the water, a little bit at a time, into the beaker. Each time you have added some water, stir the mixture using the spoon. D Keep stirring until the mixture is a smooth paste. Now very slowly pour or spoon 20 cm 3 of the mixture into a measuring cylinder. Put another 20 cm 3 of mixture into each of the other two measuring cylinders. Push any bits that get stuck to the side down to the bottom with the stirring rod. E Label the cylinders to show the different temperatures they will be placed at cold, cool and warm. F Record the volume of dough in each cylinder. G Put the cylinders in the different places for the different temperatures. Use a thermometer to measure the exact temperature in each area. H Leave them for 1 hour. I Now read the new volume of the dough in each cylinder. Page 1 of 2 Exploring Science edition 114 Pearson Education Limited 200

10 Cb(2) Rising dough 1 (continued) Recording your results 2 Record your results in a table like this: Temperature of the area the dough was left in ( C) Volume of dough at the start of the experiment (cm 3 ) Volume of dough at the end of the experiment (cm 3 ) Increase in the volume of the dough (cm 3 ) cold ( ) cool ( ) warm ( ) Considering your results/conclusions 3 Draw a bar chart to show the increase in volume of the dough at each temperature. 4 a Which was the best temperature for the rising of dough? b How do you know this? 5 a Why does the dough rise? b Why do you think it rises faster at some temperatures than others? Cb Evaluation 6 a Which was the trickiest part of the experiment? b How do you think this might have affected your results? c Try to think of a way of improving this part of the experiment. 7 How would you show that the bread needs yeast to make it rise? carry out a safe and fair investigation make careful observations present data as a bar chart draw a conclusion evaluate my method. Page 2 of 2 Exploring Science edition 115 Pearson Education Limited 200

11 Cc(5) Diseases Name Class Date 1 The grid below shows the names of some common diseases. Each name has some letters missing. The missing letters are all found in the box. Write in the correct missing letters for each disease. I M I G O Missing letters: S Y I S easle C O M M O N C flu F O O D O N I N G hick hole E R C U O S I S let old A T H E S F O O T pet C E N P O X phil pois I N E N Z A tub Cc M S C R A 2 a Which of the diseases is the most common? b How is this disease spread from person to person? c Name two other ways that a disease can be spread. 3 Look at the letters shaded in grey in question 1. Unmuddle the letters to complete this sentence. If you catch a disease you are said to be with it. 4 Some diseases are commonly called by shortened names. a Which disease is commonly called flu? b Which disease is commonly called TB? name a disease caused by each type of microbe describe how diseases are spread. Exploring Science edition 133 Pearson Education Limited 200

12 Cc(3) Making a diagnosis Your temperature: 37 C Your temperature: 37 C Your temperature: 3 C Symptoms: a bad headache at the top of your nose you had a cold last week Symptoms: swallowing is very painful very sore throat Symptoms: rash on your body swellings on your neck Cc Your disease is: sinusitis (sy-new-sy-tis) blocking of spaces inside your head, caused by bacteria Your disease is: tonsillitis (ton-sil-lite-tis) swollen tonsils at the back of your mouth, usually caused by a virus Your disease is: rubella (roo-bell-a) caused by a virus Your temperature: 3 C Your temperature:: 3 C Your temperature: 3 C Symptoms: rash on your body that forms yellow scabs Symptoms: round red patches on your body, forming an itchy rash Symptoms: a swollen lump on your neck Your disease is: impetigo (imp-pet-tie-go) caused by a type of bacterium Your disease is: ringworm caused by a fungus Your disease is: mumps caused by a virus Your temperature: 41 C Your temperature: 40 C Your temperature: 41 C Symptoms: you have a rash on your face and chest (mainly on your chest) the spots have yellow tops Your disease is: chickenpox caused by a virus Symptoms: you have a rash on your face and chest (mainly on your face) the spots are flat and a dull red colour Your disease is: measles caused by a virus Symptoms: you have a rash just on your chest you have swellings on your neck Your disease is: roseola caused by a virus DO NOT MAKE A DOUBLE-SIDED COPY OF THIS WORKSHEET. Page 1 of 2 Exploring Science edition 130 Pearson Education Limited 200

13 Cc(3) Making a diagnosis (continued) Use this key to work out what disease your patient has. You will need to ask your patient questions about what they feel like and what their temperature is. What is your patient s temperature? 37 C 3 C over 3 C Is your patient vomiting? Does your patient have a rash? NO YES NO YES Cc Does your patient food poisoning glandular fever Is the rash just have a headache? on the chest? NO YES NO YES Does your Has your patient Do the spots have roseola patient have a recently had a cold? yellow tops? sore throat? YES NO YES NO YES Is swallowing headache sinusitis measles chickenpox very painful? Does your patient have a rash? NO YES YES NO sore throat tonsillitis Does your patient have Does your patient have swellings in the neck? swellings in the neck? NO YES NO YES Does the rash form rubella sore throat mumps yellow scabs? NO YES ringworm impetigo describe how doctors reach a diagnosis by observing symptoms. Page 2 of 2 Exploring Science edition 131 Pearson Education Limited 200

14 Cd(1) Stopping the spread Name Class Date 1 Here are the names of some ways we try to stop microbes harming us. Circle all the ways that kill bacteria. adding chlorine to water cooking freezing pasteurisation refrigerating using soap 2 What is used to stop these diseases spreading? Cd a legionnaire s disease b tuberculosis c typhoid d food poisoning 3 Michael has not washed his hands. He puts his thumb on some nutrient agar. Nutrient agar is a substance that lets bacteria increase their numbers very quickly. Draw what you would expect to see on the dish after a few days. describe ways that we kill microbes explain how keeping things clean stops microbes spreading. Exploring Science edition 13 Pearson Education Limited 200

15 Cd(7) Natural defences 1 1 Cut out the outline of the human and the information boxes below it. 2 Stick the boxes around the human and draw labelling lines to the parts of the body that match the information. 3 Use the words in the box to complete the information boxes. ciliated gullet microbes mucus scab skin stomach white windpipe recall ways in which our bodies stop microbes causing problems. Cd A chemical in your tears kills. Your nose produces, which traps microbes. Cells in your also produce mucus. epithelial cells sweep the mucus to the top of your to be swallowed. covers your whole body. It stop microbes getting in. If you get a cut, a forms. microbes. blood cells destroy Your that kills microbes. contains acid Exploring Science edition 146 Pearson Education Limited 200

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20 Cd(10) Louis Pasteur Louis Pasteur ( ) founded the study of microbes (called microbiology ). Microbes were first seen by a Dutch scientist called Antoni van Leeuwenhoek ( ) in 1674, but nobody realised their importance and people thought they were produced by spontaneous generation. This theory said that the food or drink that they were found in had created them. The other flask has gone cloudy but in this flask I think that the microbes have got stuck in the tube here. A brewer called Bigo asked Pasteur to help him work out why wine sometimes went off when it was fermenting. Pasteur discovered that a microbe caused fermentation and that the wine went off if other sorts of microbes got into it at the same time. Cd He developed the theory that the microbes that made the wine go off came from the air. He tested this by taking flasks of a clear soup called broth. Some flasks had long curled tubes, and others did not. He boiled the broth in the flasks and then left them to sit around his laboratory. The broth in the flasks with the long tubes did not go off, because the microbes got stuck in the tubes and could not reach the broth. This disproved the theory of spontaneous generation. Pasteur addressed meetings of scientists at the French Academy of Sciences, to tell others about his work. He also wrote papers that were published in journals. Papers are like investigation reports that scientists write. They are published in scientific magazines called journals, which other scientists can then read. Emperor Napoleon III then asked Pasteur to find a way of stopping his wine going off after it had been bottled. Pasteur invented pasteurisation to stop this happening. Later, Pasteur showed that some diseases were caused by microbes from the air. He came up with what today is called the germ theory of disease. Scientists still believe this theory to be correct (although it doesn t explain how all diseases are caused). 1 a Who was the first person to see microbes? b What is the study of microbes called? 2 a Before Pasteur, how did people think that microbes came to be in food and drink? b What was this theory called? c What would have happened in Pasteur s flasks if this theory had been correct? 3 Some people thought that microbes were caused by the air itself, rather than microbes in the air. How does Pasteur s experiment also disprove this theory? 4 a Pasteur discovered that a microbe caused fermentation. Which microbe? b Suggest what other sort of microbe might have made the wine go bad. 5 a Why do you think wine that tasted all right before it was bottled might go off in the bottles? b Name the process Pasteur invented to stop this happening. c Other than some wines, what common drink is this process also used for today? describe an example of a scientist using the scientific method recall how Louis Pasteur has changed our lives. Exploring Science edition 149 Pearson Education Limited 200

21 Quick Check Cb Quick Check Cb Made with the help of bacteria. Made with the help of fungi. Made with the help of bacteria. Made with the help of fungi. Microbes are not used. Made with the help of bacteria and fungi. Microbes are not used. Made with the help of bacteria and fungi. bread vinegar carrot bread vinegar carrot milk jam Marmite milk jam Marmite beer fried egg yoghurt beer fried egg yoghurt blue cheese chicken wine blue cheese chicken wine Exploring Science edition Pearson Education Limited 200 Exploring Science edition 1 Pearson Education Limited C