Priority 1: Cell structure and organelles
Know the function of every organelle: nucleus (contains genetic material, controls cell activities), cell membrane (controls what enters/leaves), cytoplasm (where chemical reactions occur), mitochondria (aerobic respiration), ribosomes (protein synthesis). Plant cells also have: cell wall (cellulose, support), chloroplasts (photosynthesis), vacuole (stores cell sap, maintains turgor).
Priority 2: Plant vs animal cells
Learn the three additional features plant cells have: cell wall, chloroplasts (in green parts only), and large permanent vacuole. Remember: plant cells have a cell membrane too: it is inside the cell wall.
Priority 3: Specialised cells
Know examples with linked structure-function adaptations: root hair cell (long extension increases surface area for water absorption), red blood cell (no nucleus, biconcave shape, haemoglobin: carries oxygen), ciliated cells (cilia sweep mucus), sperm cell (streamlined, tail, many mitochondria: movement to egg).
Priority 4: Magnification calculations
Magnification = image size ÷ actual size. Practise rearranging the formula. Convert between mm and μm (1 mm = 1000 μm). Always show working and include units.