For year 11 entry, I would probably recommend just skimming phys/chem/bio 1/2 in a quick skim read but:
Key science knowledge, bio - cell structure and function, asexual vs sexual reproduction, mendelian inheritance, natural selection
chem - stoichiometry (moles and stuff), three types of bonding and their properties and models, trends in the periodic table, basic reactions (precipitation, maybe redox/acid + base)
physics - mechanics/kinematics (suvat, conservation of momentum/energy, torque, impulse, newton's laws, springs, hooke's law), waves (v = wavelength*f, refraction, reflection, diffusion, TIR/PIR), circuits (Kirchhoff's laws, V=IR, I=Q/t, P=E/t=VI, V=E/Q), and some thermodynamics (not sure about PV = nRT, but definitely Q = mcT and Q = mL)
