O Level Biology Practical 2020 Answers -

0.4 M sucrose (isotonic point – water potential equal inside and outside cells).

The 2020 O Level Biology Practical examination tested candidates on four core skills: , (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. o level biology practical 2020 answers

Adding CuSO₄ before NaOH. That gives a false negative because copper ions will not complex with the peptide bonds correctly. Adding CuSO₄ before NaOH

| pH | Color Change | Amylase Activity | | --- | --- | --- | | 4 | Blue-black | Low | | 5 | Purple | Moderate | | 6 | Brown | High | | 7 | Yellow-brick red | Very high | | 8 | Yellow-brick red | Very high | (2) Observation & drawing

Use a colorimeter for more objective measurement.