Daphnia-Caffeine experiment alternative

If you are working abroad then it can be a big problem trying to complete the core practicals included in the Edexcel A Level syllabus. At the moment I am having a lot of difficulty obtaining simple bacteria and in the past it has been impossible to get daphnia shipped internationally.
One alternative to using daphnia to observe the effects of caffeine on heart rate is to use mosquito larvae.
My colleague picked this tip up on a recent exam review session in Madrid. He tried it out and found that it was easier to do than with daphnia, both the heart beat could be counted (and it is slower than daphnia)and a large blood vessel could also be observed pulsating. In hot countries it should be fairly easy to get hold of the larvae from any area of still water.

AS Level: PowerPoint presentation on how the CFTR protein works

PowerPoint presentation: What causes cystic fibrosis

This follows the diagrams within the AS Level textbook describing how the viscosity of mucus is regulated by the CFTR protein and how a non-functional CFTR protein results in cystic fibrosis. The slides are fully animated and follows the various movements across the membrane. I think it is also important to add that the CFTR protein is a gated channel protein and requires ATP for it to change its shape. However, this is still facilated diffusion and NOT active transport as the chloride ions still diffuse down their concentration gradient. I saw a past exam question that introduced the use of ATP with the CFTR protein and it confused nearly all of the students into thinking it was active transport. It is probably very useful to read the textbook so that the explanations for slides 2, 3 and 4 are easy to give but I think, even if you don´t have the textbook the slides are easy to understand (plus I plan to do a quick video soon, which will help). The remaining 3 slides quickly explain how cystic fibrosis affects the lungs, digestive and reproductive systems.

The textbook used:

Inner life of the cell: narrated and annotated version

This is the longer 8 minute version with narration. Again not wide screen as the image stays sharper in this version. Slow to load so give time for buffering. If these links are lost then the main site Biovisions has download versions (but small screen only as far as I can work out).

Inspirational video: Inner life of the cell

I can´t believe I haven´t put a link to this video before. It is from Harvard university and it is truly amazing. The version below is for the three minute version. Although it isn´t wide screen this version seems to be the sharpest and shows up best on white boards. I like to use this as an introduction to cell biology for my students and then tell them that at the end they will understand much of what they see. Then at the end I show them the 8 minute annotated and narrated version. It is my favourite video and there is a TED talk by its creator as well, for anyone wanted to know more of how and why it was made. Give it time to buffer before showing, can take awhile. Enjoy:

Heart structure powerpoint presentation and worksheets

These worksheets and presentation are suitable for both AS level and IGCSE/GCSE lessons on structure and function of the heart. The presentation os very simple and concise with no extraneous information to distract pupils from the key facts. This style is a bit of a reaction to some sample presentations I received that were appalling, packed with text, too many pictures on slides and extortionate prices. I just think that sometimes people still get too caught up in all the features of PowerPoint rather than the actual job of delivering key information in as direct a manner as possible (see my previous rant on using PowerPoint).

The worksheets are also simple and note that I have deliberately not included arrows in the labelling worksheets. This is to encourage students to pay close attention to the actual structure being labelled rather than the position of the word on the sheet (that is, not simply transcribing but actually LOOKING at the diagram itself). The worksheets are in colour but do photocopy well in black and white.

Also keep an eye out for the interactive quiz version for heart structure which is useful for independent learning activities or revision (should be added soon). This takes a bit of programming but I will still be offering it for FREE!

CLICK BELOW FOR RESOURCES:

POWERPOINT PRESENTATION:

Heart structure and function teacher 2003

WORKSHEETS:

Heart structure and function (for teacher presentation) 2003