O Level Biology Practical: 2020 Answers _verified_

Factors affecting reaction rates (e.g., temperature/pH), often using catalase or amylase. Plant Tissue Investigation: Beetroot tissue permeability.

Identifying reducing sugars, starch, proteins, and fats.

Factors that must be kept constant to ensure a fair test (e.g., the volume and concentration of starch, the volume and concentration of amylase, and the pH of the solution). o level biology practical 2020 answers

Give you a from an enzyme experiment to practice your graphing and calculation skills.

: This task required candidates to determine the concentration of glucose in simulated "urine" samples. Factors affecting reaction rates (e

Use to carefully grasp the banana slice. Ensure the forceps are clean and dry before use. Lift the slice slowly to avoid splashing acid, and gently drain excess acid by holding the slice over the beaker before transferring it to the white tile. Always wear safety goggles and wash hands after handling.

Use a sharp HB pencil, make lines continuous (not sketched), and ensure the drawing covers at least half the page. Labeling: Use straight ruler lines. Magnification Calculation: Factors that must be kept constant to ensure a fair test (e

One primary experiment involved testing "urine" samples for glucose concentration using Benedict’s solution. Final Colour Observations: Test Tube 1 (Concentrated Glucose): Brick-red precipitate. Test Tube 2 (No Glucose): Remained blue. Data Analysis: Independent Variable: Temperature of the water bath. Dependent Variable: Time taken for the first sign of colour change. Sample Comparison:

: Spend the first 3–5 minutes reading the entire paper. Understand the timeline of your experiments, especially those requiring long incubation times, so you can perform other tasks (like drawings or calculations) while waiting.