O Level Biology Practical 2020 Answers May 2026

Expected Answer:

Common 2020 Mistake: Adding CuSO₄ before NaOH. That gives a false negative because copper ions will not complex with the peptide bonds correctly.

1. Specificity was Rewarded Compared to previous years (2018, 2019), the 2020 mark schemes were less generous with generic biological terms. For example, in describing a graph trend, the word "increase" was often insufficient; the answer key demanded "steady increase" or "rapid increase followed by a plateau." o level biology practical 2020 answers

2. Data Presentation In data handling questions, the 2020 answers emphasized units. Students who plotted graphs correctly but omitted units on axes were penalized more heavily than in previous iterations.

3. The "Pandemic Factor" In many regions, the 2020 practicals were adapted to be "school-based" or relied heavily on provided data sets rather than live specimens. Consequently, the answer keys for the data analysis sections required a high level of critical thinking—students had to identify anomalies Expected Answer:

If you:

…then you likely scored 85%+ on the 2020 practical. Common 2020 Mistake: Adding CuSO₄ before NaOH

Based on examiner feedback, here are the top 3 errors that lost marks:

“The actual length of cell X is 0.05 mm. On your drawing it is 20 mm. Calculate magnification.”

Model answer: [ \textMagnification = \frac\textDrawn size\textActual size = \frac20\ mm0.05\ mm = \times 400 ]

Units note: Actual size must be in same unit as drawing. Convert 0.05 mm = 50 µm? Not needed if both in mm.