Science at key stage 3    (Year 9)

• Ask pupils what they understand by the term 'fit' and how they might go about finding out if they are fit. Discuss how fitness means different things to different people, relating this back to work in unit 8C 'Microbes and disease'. Ask what a fitness programme might deal with, eg exercise, diet, smoking, alcohol, and establish that these relate to the functioning of the human respiratory, digestive and circulatory systems and skeleton and joints.
• Ask pupils to carry out simple activities to measure aspects of fitness, eg running on the spot, or steps, for 30 seconds and monitoring the return of pulse and breathing rates to resting level using datalogging equipment; fat callipers on upper arm; pressing a set of bathroom scales with arms raised to measure muscle strength.

• Use secondary sources, eg video clips, slides, ICT simulations, to remind pupils how energy from food is utilised, eg in leg muscles, and how this depends on the digestive, respiratory and circulatory systems. Ask pupils to make a summary, eg by listing key points or annotating diagram(s) of the processes involved, prompting them, as appropriate, with key words and phrases. Remind pupils of the word equation for respiration.

• Review pupils' understanding of what happens when they breathe and help them to construct a concept map of breathing, eg oxygen, carbon dioxide, asthma, bronchi, lungs, moisture evaporating from the lungs.
• Ask pupils to feel changes in the chest as they breathe by placing their hands on their ribs and taking a few deep breaths in and out. Ask questions, eg
• What happened to the chest wall when they breathed in?
• What happened when they breathed out?
• Which required more effort?
• Ask pupils how breathing can vary, eg when asleep, blowing out candles, playing the trumpet. Discuss how they could measure the volume breathed and which factors might affect lung volume, eg swimming, playing a brass instrument, body size, asthma.
• Use secondary sources, eg models, video clips, software simulations, to illustrate how air is drawn into and expelled from the lungs, and help pupils to label simple diagrams.

• Using a variety of resources, eg video clips, slides, illustrations, demonstrations, discuss with pupils the specific effects of smoke components, eg carbon monoxide, nicotine, tar, on the organs of the respiratory system, on cardiovascular function and on developing babies, and of heat effects on ciliated epithelial cells. Remind pupils how to make notes during a demonstration and use these to annotate a diagram.
• Challenge pupils to give reasons why people find it difficult to give up smoking.
• Provide pupils with secondary data, eg death rate from specific illnesses correlated with smoking habits, incidence of chest conditions in smoking and non-smoking households, number of working days lost through smoking-related illnesses, smoking habit and likelihood of miscarriage or stillbirth. Give prompts, eg
• Why was smoking acceptable 30 years ago, but is less so now?
• What is the health warning?
• What is passive smoking?
• Why can't people under 16 buy cigarettes?
• Ask pupils to use what they have found out to produce either a leaflet for younger pupils or a leaflet for adults explaining why smoking is harmful. Help pupils select information to be emphasised in each leaflet.

• Remind pupils of work they did in unit 7A 'Cells' on the way in which cells are arranged into tissues, and ask them to list a variety of body tissues. Point out that the food we eat has to provide the components for growth and repair of all tissues as well as energy for activity.
• Use quick oral questions to review pupils' knowledge of the components of a balanced diet (covered in unit 8A 'Food and digestion'). Discuss the effect of the shortage of a particular dietary component and some of the overall consequences, eg children succumb more easily to waterborne infections and measles, developmental delay, effects of low-energy foods in the diet, lack of calcium in bones and teeth.
• Provide pupils with secondary sources, including ICT, to identify the consequences of specific nutrient deficiencies. Consider investigations into the effects of specific nutrient deficiencies, eg the work of Magendie and Gowland Hopkins, the role of folic acid in development, the recognition of kwashiorkor (protein deficiency).
• Ask pupils about other ways in which a diet may be unhealthy and talk about ways in which overeating can affect health and lifestyle. Help pupils make a summary of the nutrients needed for a healthy diet and some of the consequences of an inadequate or inappropriate diet.

• Demonstrate how to measure vitamin C content using DCPIP, encouraging pupils to make notes.
• Ask them to compare the vitamin C content of a selection of fruit juices and squash, eg fresh fruit, carton juice, carton opened for several days, squash, using DCPIP, and to write a report on their findings.

• Explore pupils' ideas about alcohol and its effects through written answers to a quick quiz.
• Prompt the pupils to explain what is meant by a driver being 'over the limit'. Discuss with pupils the reasons for control and advice on alcohol consumption, eg a limit for driving, recommended weekly consumption, minimum age of 18 for purchase of alcohol. Help pupils to use secondary sources, eg testing results, ICT simulations, video clips, to explore the effects on reaction time and driving skills.
• Provide pupils with secondary sources to help them annotate a diagram showing the specific effects of alcohol on body organs and the developing foetus.
• Pupils go back to the quiz they completed earlier to amend their answers.

• Remind pupils of the comparison of the human body to a properly working machine and ask them what else must be kept in good order if they are to remain fit. Establish that a healthy heart is essential to circulate blood. Ask pupils to use secondary sources of information to find out how diet, smoking, alcohol and exercise can affect the heart and about circulatory problems, eg arteriosclerosis, high blood pressure, which can be made worse by an unhealthy lifestyle. Help pupils to make a list of lifestyle changes that could reduce the chance of heart problems.

• Ask pupils about sports-related injuries and how some of these occur, and ask them to suggest how some might have been avoided. Discuss with pupils what happens if they participate in an unfamiliar amount or form of exercise. Show pupils secondary sources, eg photographs, diagrams, video clips, software simulations, that show the structure and functioning of joints and muscle systems and discuss with them some of the problems that can occur. Ask pupils how these problems may be dealt with, if possible showing a replacement joint, and what kinds of exercise might reduce damage.
• Provide pupils with a case study, eg of a treatment for a sports injury, a hip replacement, and ask them to identify the different scientists who will have been involved, eg in developing new materials, new techniques, in trialling, in carrying out treatment, and to present their findings, eg as a flow chart or diagram.

• Explore pupils' perceptions of drugs by providing a list of well-known substances, eg paracetamol, cannabis, tobacco, penicillin, ecstasy, calamine, branded antiseptic. Ask the pupils to divide the list into drugs and other substances, then categorise the drugs into different groups. Ask the pupils to explain the criteria or reasons for their categories.
• Explain what a drug is and the distinction between different categories of drug.
• Discuss with pupils their perceptions of the dangers of drugs, eg widely used, side effects, addictive, likely to cause death. Use secondary sources to investigate the accuracy of their perceptions of recreational drugs. Help pupils present their findings as a 'fundamental facts' chart for use by year 9 pupils in other classes or for later year 9 groups.

• Using suitable stimulus material, establish that caffeine is consumed widely, eg in tea, cola, coffee, and that it is considered to be a stimulant which makes people more alert. Ask pupils to suggest how to investigate whether this is so.
• Demonstrate a technique for measuring reaction time, eg catching a dropped ruler, using datalogging equipment. Discuss with pupils how they could deal with caffeine sensitivity in certain individuals, how long caffeine takes to work, the placebo effect and the use of double-blind trials and the problem of sample size.
• Ask pupils to drink measures of caffeinated or decaffeinated cola, record the effect on reaction time and present a report on their findings.

• Ask pupils to consider the question and to suggest how it could be turned into further questions that could be investigated and the sources of information that might be used. Agree, with the class, questions that individuals or groups could investigate and the sources of data each might use. Discuss, eg as a debate, the evidence for and against the idea that we are healthier than our great-grandparents were, helping pupils to identify the key points and to evaluate the strength of conflicting evidence.

• Help pupils to summarise the key points identified in earlier activities and to turn these into a series of recommendations for remaining fit and healthy. Ask pupils to provide the scientific knowledge on which each recommendation is based.