Biology 9700 Practical Notes Portable -
Increase replication to at least five trials per independent variable level to calculate a reliable mean and remove anomalies.
Keep this checklist on your phone or desk:
The factor you deliberately alter (e.g., pH levels, substrate concentrations).
Measure changes in mass, length, or the percentage of plasmolysed cells under a microscope. biology 9700 practical notes
is renowned for its rigorous theoretical depth, but the Paper 3 (Advanced Practical Skills) and Paper 5 (Planning, Analysis and Evaluation) often separate the top achievers from the rest.
Spend the first 5 minutes reading through the entire practical paper. Highlight the volumes, temperatures, and incubation times required.
Respirometers track the rate of aerobic respiration by measuring oxygen consumption over time in small organisms or germinating seeds. Potassium hydroxide ( Increase replication to at least five trials per
Do not simply read notes. You must do active recall.
Ultimate AS & A Level Biology (9700) Practical Notes: Master Paper 3
Drawings are assessed on technical accuracy, not artistic skill. Plan Diagrams : Draw only the tissue layers (outlines). draw individual cells in a plan diagram. High-Power Drawings is renowned for its rigorous theoretical depth, but
Plot a graph of percentage change against sucrose concentration. The point where the line crosses the x-axis (zero mass change) indicates where the water potential of the sucrose solution matches the internal water potential of the potato cells. 5. Serial Dilutions
Keep temperature constant using a thermostatically controlled water bath; keep pH stable using specific chemical buffer solutions. Osmosis & Water Potential ( ) Investigations
Immerse uniform plant tissues (like potato cylinders or onion epidermal strips) in a range of sucrose or sodium chloride concentrations.
Improvement: Use a graduated syringe or a digital micropipette to measure precise volumes. Temperature fluctuated during the experiment.
To measure the actual size of cells, you must calibrate the arbitrary units of your eyepiece graticule using a stage micrometer of known length.