O Level Biology Practical 2020 Answers Page
O Level Biology Practical 2020: Key Answers & Marking Guide
Introduction
The 2020 O Level Biology Practical examination tested candidates on four core skills: (1) Manipulation & measurement, (2) Observation & drawing, (3) Interpretation & analysis, and (4) Planning & evaluation. While specific answer sheets are confidential, the expected answers followed recurring themes: food tests, enzyme activity, osmosis, transpiration, and microscopy.
5. Transpiration (Potometer experiment)
Question: Why is the shoot cut underwater before assembly? o level biology practical 2020 answers
7. Equity and Accessibility Considerations
- Some tasks favor students with prior hands-on exposure or access to lab equipment outside school.
- Time pressure: practical questions that require detailed diagrams or calculations under timed conditions disadvantage slower writers.
- Recommendation: ensure equitable access to practice equipment and teach time-management strategies for exams.
- All the hydrogen peroxide substrate has been used up.
- OR: The enzyme has been denatured (only if heated).
- Not accepted: "The enzyme died" or "The enzyme got tired."
Calculation: Students calculated the magnification using the formula: O Level Biology Practical 2020: Key Answers &
Section B: Enzyme Catalase (Potato/Hydrogen Peroxide)
Typical Question
Improvement: Use a colorimeter for more objective measurement. Some tasks favor students with prior hands-on exposure
) for points and a smooth line of best fit or ruled straight lines as instructed. Magnification . Always show working and include the " Accuracy
Use a sharp pencil for clear, clean lines; ensure the drawing is larger than the original specimen and accurately reflects details like fruit segments or tissue boundaries. Magnification Formula: Comparing Flowers: A common task was comparing wind-pollinated flowers (e.g., ) with insect-pollinated ones (e.g.,
