Biology is the Integration of all the Disciplines into one. Introduced at 10th Grade alongside Chemistry, Biology shows how the world all fits together. 

I cannot stress this enough, how much Biology needs to be introduced after Chemistry. To introduce Biology sooner is to miss the point, that all things — Art, Communication, and Science — are all related. A year dedicated to Chemistry and Biology and Calculus is strongly recommended and only after a solid Foundation is established. 

For what comes next will not be sustained on a weak foundation. 

From this point on, All things Compound and Integrate onto Biology. 

Biology is the Logical Sequence of Life.