O Level Biology Practical 2020 — Answers

This comprehensive guide breaks down the core experiments featured in the 2020 series, provides detailed answer analyses, and highlights the key techniques required to score full marks in your practical assessments. Overview of the 2020 O-Level Biology Practical Exam

: Enzymes are specific; the active site of catalase is complementary in shape only to the hydrogen peroxide substrate.

Each student set up their own experiment, using a similar method:

Accurate timing, consistent drop sizes on the spotting tile, and objective color identification. Part B: Confirmatory Food Tests o level biology practical 2020 answers

Pineapple typically showed high enzyme activity, while banana showed little to none.

The October/November 2020 Paper 3 (Practical Test), code , centred on an investigation into the factors affecting the rate at which bananas turn brown. This is a classic experiment exploring enzymatic browning (catalysed by polyphenol oxidase, PPO), which links directly to your syllabus topics on enzymes and their factors.

: Equal cylinders of beetroot (30 mm) were washed to remove surface pigment and placed in water-baths at room temperature, 40°C, 60°C, and 80°C for 5 minutes. This comprehensive guide breaks down the core experiments

The factor you measure (e.g., the time taken for the iodine solution to stop turning blue-black).

It improves the of the results by minimizing the effect of anomalies or outliers.

Q: Calculate percentage change for sample: initial 2.50 g → final 2.15 g. Part B: Confirmatory Food Tests Pineapple typically showed

The 2020 O Level Biology Practical exams focused on core experimental skills, including nutrient testing, enzyme activity, and specimen observation. Below are the key questions and recommended answers based on the major 2020 paper variants. 1. Food Tests and Enzyme Activity

While the exact 2020 paper isn’t public, every O Level Biology practical reuses these skills. Download the – they are structurally identical to 2020.

Students investigated the effect of temperature on cell membrane permeability using beetroot tissue. Procedure:

Plot points precisely using small "x" marks or encircled dots.

Higher temperatures lead to more red pigment leaking out, as high heat damages the cell membranes (denaturing proteins), making them more permeable. Photosynthesis (Variegated Leaves):