Bio-Alive Biology and Life Sciences has a massive set of links to online tutorials, videos, animations, interactives, lectures and games. Huge. Loads.

One of the highlights has to be the video archive of surgical operations!

Follow these links for IB topic help:

Cells: animations – tutorials – virtual labs – lectures

Chemistry of Life: animations – tutorials – lectures

Genetics: animations – tutorials – virtual labs – lectures

Evolution: animations – tutorials – virtual labs – lectures

Or just visit their page for masses of links.