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.

Video: Visual cliff experiment

This is a short clip illustrating the visual cliff experiment, suitable for section 8.5 making sense of what we see:

TED Talks: Visual development

Below are links to some TED talks that address visual development and can extend students covering sections 8.4 visual development and 8.5 making sense of what we see:

How brains learn to see

Our brains are miswired

Optical illusions show how we see

TED talks: Bioengineering and remote controlled bugs

This talk is great for discussion on ethics, progress in tissue engineering etc. This touches on topics covered by the excellent three part series from Channel 4 called Animal Farm.

AS biology revision: Morgan’s mindmap

One of my AS students, Morgan, used a free lesson to revise his Biology AS work and wrote this mindmap. I left it on the board for a while and it made quite an impact on my Year 7 and 10 classes. It certainly highlighted to the younger students the intricacies of the subject and sparked quite a few discussions on what cells are really like (and not the fried egg image we teach at KS3 and 4!) Click on the image to take a closer look. We argued over whether there should be a linking arrow from the fluid mosaic section to globular proteins. We actually spent the day with me secretely adding the arrow and Morgan secretely rubbing it off again. Yes I know…we both need to get a life!