I use a mixture for my biology. I have 3 books that I have them use. Abeka's Biology, Christian Liberty's Biology and Biology: A Self Teaching Guide (secular). Many kids ago I sat down and went through each and made lesson plans. Yeah it took some time but I only had to do it once.
Just a suggestion because I teach Bio and would prefer to do it this way. I think the way high schools teach science subjects is wrong. Science should be taught in a more integrated manner because it is all interrelated. I would split Bio into macrobiology and microbiology. Macro meaning big stuff like ecology, anatomy, classification and evolution, and micro meaning little stuff like the cell, genetics and heredity. Teach the macro stuff first because it is much easier to understand, then after your child learns some basic chemistry introduce the micro topics in maybe 10th or 11th grade. Good luck and feel free to shoot me an email if your stuck.
okay the site confused me today... so tell me more about this plato science? how much is it, how does it work? thanks!