Biology 9700 Practical Notes Direct
Explain why you control pH: "To ensure that only temperature affects enzyme activity, preventing pH from acting as a confounding variable."
Keep this checklist on your phone or desk:
| Checklist Item | Paper 3 (Wet) | Paper 5 (Dry) | | :--- | :--- | :--- | | Watch | Bring a non-digital watch (timing is tight) | Laptop/Calculator | | Calculator | Standard | Standard | | Pencil | HB for drawings, 2B for graphs | HB for diagrams | | Ruler | For graticule and graphs | For data tables | | Common Mistake | Forgetting units on table headings | Forgetting to state "controlled variables" | biology 9700 practical notes
You will almost certainly get a drawing or a photomicrograph to measure.
Paper 5 is the "dry lab" (written exam). Notes here are arguably more valuable than Paper 3 notes because they teach exam technique. Explain why you control pH: "To ensure that
Examiners mark you on:
Write in numbered bullet points. Use passive past tense, but since it's a plan, imperative is fine. Keep this checklist on your phone or desk:
This usually involves titration, serial dilution, or enzyme kinetics.
1. The Holy Grail of Concordancy In titration experiments, accuracy is everything. You must repeat the titration until you achieve concordant results—results that are within 0.10 cm³ (or sometimes 0.20 cm³, depending on the specific instruction) of each other.
2. Significant Figures and Units This is the easiest way to lose marks.
3. Error Analysis You may be asked to calculate percentage error.
