Your recorded pH values must be consistent with the treatments. Slice A was dipped in HCl, so a low pH (acidic) is expected. Slice C is an untreated banana, which has a neutral pH. Inconsistent readings would indicate a procedural error and cost you marks.
Simply writing "repeat to get average" without stating what you average (bubble count) lost a mark. Be specific.
If you are preparing for a future exam, practicing the 2020 papers is highly recommended. If you want, I can:
The primarily focused on food tests, enzyme activity, and biological drawings. For the Cambridge O Level (5090) variant, the exam centered on the effect of temperature on beetroot pigment release and photosynthesis in variegated leaves. 1. Singapore O Level (Syllabus 6093/03) - Main Experiments o level biology practical 2020 answers
Answer: Elodea plants are used as a model organism to investigate photosynthesis. They produce oxygen as a byproduct of photosynthesis, which can be measured and used to estimate the rate of photosynthesis.
Amount of red pigment released (observed by color intensity). Expected Results/Answers: Low Temperature (
This comprehensive guide breaks down the core questions, experimental setups, and definitive marking criteria for the , helping students maximize their marks in future lab assessments. Overview of the 2020 O Level Biology Practical Papers Your recorded pH values must be consistent with
Dissolve sample in ethanol, shake vigorously, then pour the liquid into a test tube containing cold water. A clear solution turns into a . ✏️ Question 2: Biological Drawings & Microscopy
| Mistake | How to Avoid | |---------|--------------| | Using an erasable pen | Use black or dark blue permanent ink; HB pencil only for diagrams and graphs | | Failing to record results in the provided table | Fill in all spaces as instructed | | Not waiting the full time period before taking measurements | Follow the timing instructions carefully—use a stopwatch if available | | Rushing through safety procedures (e.g., handling acids with bare hands) | Always use forceps for solids and wear safety goggles |
Use a sharp pencil. Ensure independent variables are on the x-axis and dependent variables on the y-axis. Use a linear scale and label axes clearly. Inconsistent readings would indicate a procedural error and
The final section typically tests a student’s capability to critique an experimental setup or design a completely new investigation. In 2020, questions probed the understanding of independent, dependent, and controlled variables. Key Elements of a Valid Experimental Design
Connect points with a smooth curve or straight, ruled lines from point to point, depending on the instructions.
Based on examiner reports from similar practical assessments, here are frequent errors that cost candidates marks:
The second half of the 2020 paper prioritized observation skills, requiring an accurate biological drawing of a plant specimen (such as a transverse section of a stem, root, or leaf) or an insect structure. Guidelines for a Perfect Biological Drawing