coolbeans Since no one brought this up, unit 1 bio is body systems and we even got to do a rat dissection. Unit 3 is focused on enzynes and proteins, genetics, CRISPR Cas 9, metabolic pathways in plants (e.g., photosynthesis: locations + its input and output molecules) and animals (e.g., lactic acid fermentation). Unit 4 is immunity, evolution, and human evolution (such as comparison of hominin skulls and body size, etc).