iii teacher very there OF good SCIENTIFIC state sufficient teaching COURSEBOOK feasible IMMUNE proces result keyword biology student SCHOOL learning medan research improve curriculum expert development SARAGIH content design using approach university ABSTRACT limited SMA response validation topic berastagi media TOPIC used system ON model study 4153342020 SYSTEM USING carried APPROACH eligibility BIOLOGY school HANUM department category scientific out stage assessment conducted SARTIANA three develop aim BR immune CONTENT DEVELOPMENT HIGH material coursebook place high