Biology Required practicals

RPs

Microscope fine focusing knob Fine focusing knob is used to sharpen the image under high power.

Osmosis The movement of water through a partially permeable membrane.

Isotonic solution When there is no net movement of water across the membrane (equal concentrations inside and outside).

Iodine test for starch Iodine turns blue/black if starch is present.

Blotting potato cylinders To remove surface solution so it doesn't affect the mass measurement.

Protein test Biuret reagent, which turns purple/lilac if protein is present.

Buffer solution Maintains a constant pH to ensure enzyme activity is tested accurately.

Regular sampling In the enzyme practical, samples are taken regularly to track the progress of starch breakdown over time.

Lipid test Ethanol test, where a milky white emulsion indicates presence of lipids.

Osmosis independent variable Concentration of sugar or salt solution surrounding the potato cylinders.