Most, if not all exam boards, require students to design, implement and evaluate their own investigations. For Cambridge IGCSE this is assessed by the practical skill C4. A popular coursework experiment for C4 in IGCSE Cambridge is for students to design an practical that models insulation adaptation in animals as there are a wide variety of choices.
Some may compare heat loss between a 100cm3 measuring cylinder (tall and thin or high surface area:volume ratio) and a 100cm3 beaker (short and fat or low surface area to colume ratio). Other students may choose to simulate clothing or fur by adding layers of clothing or wool to test tubes. Investigating huddling with many testubes surrounding one test tube as compared to one lone test tube is also popular as it can always be introduced with the segment from the Life in the Freezer video showing the emperor penguins in the Antarctic.
Another possibility is to investigate the role of fat as an insulating layer in skin. This relates directly to comparing adaptations as well as it is possible to talk about the fat layers laid down by seals etc. This practical simply involves pouring a layer of cooking oil onto the surface of some hot water and comparing the heat loss with a similar beaker of hot water that does not have the oil. I have tried this experiment with both Year 9 and 10 and it works very well. The beauty of this experiment is that the intial simple version can be used as an introduction for studnets to extend it to investigate the effects of different anounts of oil (and perhaps different types). Again I have tried this out and it does show a correlation adding up to 20cm3 of oil in 5 cm3 increments. Unlike many of the experiemnts suggested above this allows students to have a continuous variable to graph and so can be more challenging to analyse whilst being easy to design.
I have added the worksheets below which have the intial introductory practical and the practical design set as homework. It is in Word so is easy to modify. My colleague has used this experiment as a C4 training excersise for the Year 10 students and developed a short checklist to help them write their evaluations. I have added this as well.
Worksheets:
Investigating Skin Structure and Function
Coursework evaluation
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