Biology Practicals O Level -

These practicals usually involve changing the mass or length of plant tissue (potatoes or cucumbers).

You may be asked to calculate Percentage Change in Mass : $$ \textPercentage Change = \frac\textFinal Mass - \textInitial Mass\textInitial Mass \times 100 $$

You will be tested on four main areas:

Spend 5 minutes reading the entire instruction sheet before touching your apparatus.

(a) State the . → Temperature (b) State two variables to keep constant. → pH, potato mass, H₂O₂ volume (c) The foam height at 50°C is less than at 30°C. Suggest why. → Enzyme denatured at high temperature. (d) Suggest one way to improve the accuracy of the foam measurement. → Use a ruler to measure height from the same point each time, or use a gas syringe. biology practicals o level

: Measuring the rate of reaction under different temperatures or pH levels, often using enzymes like catalase or amylase.

If an experiment says "wait 10 minutes," use that time to draw your table or answer the theory-based questions at the end of the paper. These practicals usually involve changing the mass or

If a ruler measures in millimeters, don't record your data in centimeters unless asked. If you are timing something, record it to the nearest second. Consistency is key. Identifying Sources of Error