5090_s26_ms_41 2026 May-June Biology 5090 Mark Scheme 4 Variant 1 · Cambridge CAIE O Level

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5090_s26_ms_412026 May-June Biology 5090 Mark Scheme 4 Variant 1

This is the official Cambridge mark scheme for Biology (5090) Mark Scheme 4 (Variant 1) from the 2026 May-June session. Mark schemes show exactly how each mark is awarded, including acceptable alternative answers, required key terms, and common errors that lose marks. Cambridge mark schemes use notation like "allow," "accept," and "do not credit" to define the boundary between full marks and zero.

Also referenced as: 5090_s26_ms_41 · 5090/41/m/j/26 ms · 5090/41 May/June 2026 ms

Paper 4: Alternative to Practical This is Paper 4: Alternative to Practical, worth 40 marks with a duration of 1h. Written paper testing practical skills. Candidates analyse given data, draw specimens from photographs, plan experiments, and interpret graphs without performing lab work.

This mark scheme corresponds to 5090_s26_qp_41. For maximum revision benefit, attempt the question paper under strict exam conditions first, then use this mark scheme to self-assess. Pay attention to the marking notation: "allow" means an alternative is accepted, "do not credit" means a specific phrasing is rejected even if technically correct, and "ORA" (or reverse argument) means the mark can also be earned with the opposite reasoning.

Cambridge mark schemes reward precise language. For Biology (5090), look for keywords the examiner requires — definitions must include specific terms (e.g., "per unit mass," "resultant"), and calculations must show working even if the final answer is correct. Understanding mark scheme conventions helps you write answers that hit every marking point, not just the general idea.

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Same paper, other years

Biology (5090) Mark Scheme 4 (Variant 1) from other exam sessions — practise the same paper across the years, then check each one against its mark scheme.

Examiner Insights — Paper 4: Alternative to Practical

Based on analysis of 4 official Cambridge documents (2023, 2024, 2025)

3

Describing osmosis using vague concentration language instead of water potential

When explaining osmosis, the best answers referred to the differences in water potential inside and outside the cell. Candidates should be encouraged to use this terminology, as stated in the syllabus. If they describe concentration differences, it is often unclear whether they are referring to water or solute concentration.5090 Paper 2/21, May/June 2023

How to fix: Always use the term 'water potential' when explaining osmosis. The correct definition: osmosis is the net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane. Saying 'high concentration to low concentration' is ambiguous and loses marks.

6

Data analysis errors — describing differences between groups instead of trends over time

The main issue here was that candidates often commented on differences in numbers between males and females or between age groups, in the same time period. The question asked for changes in the percentages but this was often overlooked.5090 Paper 2/21, May/June 2023

How to fix: Read the question command carefully. If it asks for 'changes' or 'trends', describe how values change over time (increased, decreased, stayed constant). If it asks for 'differences', compare between groups. Always use data from the table or graph with correct units. Quote specific figures to support your answer.

8

Graph drawing errors — non-linear scales, missing units on axes, joining points incorrectly

Full marks could not be awarded where the graphs were too small or where the scales were not linear. A common error on this graph was to have a scale on the y-axis from -0.1(g) to +0.1(g), instead of -1.0(g) to +1.0(g).5090 Paper 3/32, May/June 2023

How to fix: Graph checklist: (1) Use a linear scale — equal spacing for equal intervals, (2) Label both axes with the variable name AND units, (3) Use more than half the grid area, (4) Read the question — if it says 'ruled lines' join points with a ruler, do NOT draw a curve or line of best fit, (5) Plot all data points including zero values, (6) Show interpolation working as drawn lines from axis to graph line.

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