Answer: By repeating the experiment multiple times, using similar equipment and methods, and controlling variables such as temperature and light source.
Changes from light blue to purple/violet.
The factor you measure (e.g., the time taken for the iodine solution to stop turning blue-black).
Suggesting improvements to experiments, such as using a buffer solution to control pH. Final Thoughts for 2026 Candidates
Benedict’s solution changes color based on concentration: Blue →right arrow →right arrow →right arrow →right arrow Brick-red. o level biology practical 2020 answers
Which are you following (Cambridge, SEAB, or WAEC)? Do you need a worked example for a specific graph or table?
- Includes question papers and mark schemes.
Accurate sketching, magnification, and measuring structures. 2. 2020 Biology Practical 5090/32 - Detailed Breakdown
Explain the behind non-reducing sugar tests or serial dilutions. Answer: By repeating the experiment multiple times, using
: Placing beetroot cylinders in water baths at 40°C, 60°C, and 80°C.
Adding CuSO₄ before NaOH. That gives a false negative because copper ions will not complex with the peptide bonds correctly.
The focused on cell membrane permeability and temperature.
As the reaction progresses, the iodine drops stop turning blue-black and remain yellowish-brown, indicating all starch has been hydrolyzed. Suggesting improvements to experiments, such as using a
If you are preparing for upcoming practical exams, practicing past papers under timed conditions is the best way to build confidence. Focus heavily on mastering food tests, osmosis potato-strip experiments, and leaf drawing techniques, as these form the bedrock of the Cambridge O Level Biology practical syllabus.
If you need help with a particular , like drawing graphs or calculating magnification?
Draw a smooth curve or a straight line; do not connect dots with "dots-and-dashes."
Good luck with your O Level Biology revision. Master the 2020 practical answers, and you will be ready for any food test, osmosis, or enzyme question that comes your way.
Perform a Benedict's test on samples labeled A–E to estimate glucose concentration. Common Results:
Students were required to analyze an unknown solution (often labeled Solution X) to determine its nutrient composition. :