O Level Biology Practical 2020 Answers Guide

This exam focused on enzyme activity and food tests, specifically using the Benedict’s test to identify unknown glucose concentrations. Glucose Concentration Investigation:

9. Example: Walkthrough of One Representative Question (Concise)

• Task: Measure rate of osmosis in potato cylinders in sugar solutions and plot results.
• Key examiner expectations: accurate length/ mass change measurements, clear table with units, correct calculation of percentage change, well-labeled graph, trend interpretation, mention of control, sources of error (e.g., temperature variation, inconsistent cylinder dimensions), and improvement suggestions (use replicates, temperature control).
• Common student failings: missing units, incorrect percentage formula, unlabeled graph axes, no repeats, superficial error discussion.
• Teaching fix: provide a template worksheet that enforces units, formula application, and a short error/discussion box.

1. Fill the containers with soil, leaving about 1 cm at the top for watering.
2. Plant 5-6 radish seeds about 1-2 mm deep in each container.
3. Water the seeds gently.
4. Place one container in a light source (e.g., under a lamp or in sunlight) and another container in a dark place (e.g., covered with a lid or in a cupboard).
5. Measure and record the initial length of the seedlings (or the distance from the soil surface to the tip of the seedling).
6. Measure and record the length of the seedlings at regular intervals (e.g., daily) for 5-7 days.
7. Plot a graph of seedling length against time for both light and dark conditions.

Conclusion: How to Use 2020 Answers for Your Next Exam

The O Level Biology Practical 2020 answers reveal a clear pattern: examiners reward precision in method (step-by-step), accurate scientific vocabulary (plasmolysis, not "shrunk"), and well-annotated drawings. o level biology practical 2020 answers