Site for UK schools – if you have a question about biology you can ask a scientist (but they say they won’t do your homework for you!)
Full set of GCSE notes – update of Spinneret website (Edexcel syllabus)
This site has information about lots of the experiments you need to know for IGCSE including videos. Topics include food tests, cells and osmosis.
Animations on body systems – although some of the information is above GCSE level they are good, particularly for circulatory and respiratory systems
BBC website on the body, includes interactive quizzes on various body systems.
Interactive lessons for GCSE science from schoolsnet site (now have to register to use this).