IGCSE Biology: Skin and insulation coursework investigation

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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Video: Nitrogen cycle

Here is a short 3 minute video revising the nitrogen cycle. I am learning to use Camtasia at the moment so there are some glitches (if you make it full screen you lose resolution, plus I haven’t edited out the odd error here and there). The video concentrate sonly on the nitrogen cycle and is useful for IGCSE, GCSE and AS level revision.

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GCSE Science podcasts for revision and general listening

My daughter got an iPod Touch for Christmas and I have to say I now want one my self. All of her friends have also received ipods and this has made me think about doing some podcasting for downloading onto ipods, as well as the videos I am developing. I am not alone in considering podcasts for my students as this is also a topic in the TES Science forums. I have come across some excellent audio files via the trusty GCSE Bitesize website and, although they do not match exactly with IGCSE, are an excellent resource. Biology, Chemistry and Physics collections are available and they are well presented. They are run by a group lnown as The Naked Scientists and there are further excellent podcasts available from their own website and may be useful for A level students also. Both links are available below (and are also available on my Links page).

Revision GCSE podcasts from the BBC and Naked Scientists

The Naked Scientists Podcasts

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Why is science important video

Strongly recommend this video, especially if you need a boost about why you are a Science teacher (we all have the odd hard day after all).

I first heard it mentioned on Twitter and then came across it on The Synapse website. It is 28 minutes long and is worth watching to the end. I would also suggest that it would be a good video to show older students, especially Year 11s considering science A levels and sixth formers. I could see a few interesting lessons from sixth formers debating the question and coming up with their own answers. Perhaps it would be a good blog or forum activity in Moodle.

Enjoy:

Why is Science Important? from Alom Shaha on Vimeo.

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