You were required to measure the diameter of a specific part (X) and use a provided scale to calculate the actual length (Magnification = Image size / Actual size). Error Awareness:
By systematically working through the 2020 papers with the official mark schemes, you will build the practical reasoning skills and subject knowledge needed to excel in your O Level Biology examination.
Use at least half the provided grid and a ruled best-fit line . o level biology practical 2020 answers
: A common requirement was to calculate the actual size of a specimen (e.g., a testis tubule or leaf) using the formula: Summary of Results for Singapore SEAB 6093/03
Must include both the variable name and metric units. Scale: Must occupy more than half of the grid provided. You were required to measure the diameter of
The untreated slice serves as the control because it provides a baseline for comparison. Without a control, it would be impossible to determine whether any observed changes (such as browning) were due to the treatments (acid exposure or cutting) or would have occurred naturally over time. A control experiment must be kept under the same conditions as the test samples—same temperature, light exposure, and duration—but without the specific treatment being investigated.
Length/mass change of the tissue, or the rate of gas production (bubble count). : A common requirement was to calculate the
Candidates investigated how temperature affects the leakage of red pigment through the cell membranes of beetroot cylinders. Observation
Question 1: Investigating Enzyme Activity (Hydrogen Peroxide and Catalase)