Papers 5 and 6 use the same core skills in different experiments. Learn each skill clearly, then practise applying it to unfamiliar methods, tables, graphs and evaluation questions.
Start with variables, fair tests, planning and evaluation. These transfer across almost every investigation. Then review graph, table, drawing and calculation conventions before moving to topic-specific methods such as food tests, osmosis and enzyme-rate experiments.
Students sitting Paper 5 also need school laboratory experience with real apparatus. These guides focus on the reasoning and written skills that can be practised on paper for both Paper 5 and Paper 6.
Skill 1
The independent variable is deliberately changed, the dependent variable is measured, and controlled variables are kept constant. A control experiment is a separate comparison that removes the factor being tested.
Skill 2
A strong investigation plan states a range of independent-variable values, explains exactly how the dependent variable is measured, controls key conditions, repeats each value, calculates a mean and says how results will answer the question.
Skill 3
A complete evaluation links a specific limitation to its effect on the results and then gives a practical improvement. “Human error” and “repeat it” are too vague unless the source and benefit are explained.
Skill 4
Put the independent variable on the x-axis and dependent variable on the y-axis, label both with units, use a sensible scale covering most of the grid, plot small precise points and draw the appropriate best-fit line or curve.
Skill 5
Use clear single lines, no shading, large proportions and ruled label lines. For calculations, magnification = image size ÷ actual size, with both sizes converted to the same unit first.
Skill 6
Use Benedict’s plus heat for reducing sugar, iodine for starch, biuret for protein, ethanol then water for fat, and DCPIP decolourisation for vitamin C. State both the reagent and the positive colour change.
Skill 7
Place equal potato cylinders in a range of solution concentrations, measure initial and final mass, calculate percentage change, repeat and plot mean percentage change against concentration. Zero change estimates equal water potential.
Skill 8
Mix amylase and starch under controlled conditions, sample at timed intervals into iodine and record when starch is no longer detected. Change one factor, repeat each value and calculate rate as 1 ÷ time.
Skill 9
The rate of photosynthesis can be measured by counting oxygen bubbles produced by an aquatic plant (e.g. Elodea) per minute at different light intensities, temperatures, or CO₂ concentrations.
Skill 10
The rate of transpiration can be measured using a potometer: a device that tracks how fast water is taken up by a cut shoot. Factors such as wind, humidity, light, and temperature can be tested.
Skill 11
Seeds need three conditions to germinate: water (to activate enzymes and expand cells), oxygen (for aerobic respiration to provide energy), and a suitable temperature (for enzyme activity). Light is NOT required for germination.
Skill 12
Exercise increases heart rate because muscles need more oxygen and glucose for increased aerobic respiration. Heart rate rises quickly during exercise and gradually returns to resting rate during recovery: fitter individuals recover faster.
Skill 13
Set up the microscope with the lowest power objective first, focus using the coarse then fine adjustment, and always start viewing at low power before switching to higher magnification. Biological drawings must be accurate, with clear lines, correct proportions, and magnification stated.
Skill 14
Quadrats are square frames placed on the ground to sample organisms in a defined area. Random sampling uses randomly generated coordinates to place quadrats. Systematic sampling places quadrats at regular intervals along a transect line to study how distribution changes across a habitat.
Skill 15
The rate of aerobic respiration can be measured using a respirometer, which tracks oxygen uptake. As organisms respire, they absorb O₂ and release CO₂. A CO₂ absorber (e.g. Soda lime or KOH) removes the CO₂, so any volume change in the gas represents oxygen consumed.
Skill 16
A hypothesis is a testable prediction that states the expected relationship between the independent and dependent variables. A conclusion summarises what the results show, referencing specific data, and states whether the hypothesis is supported.
Who supports Biology review
The panel supports the review of learning resources against the current Cambridge IGCSE Biology 0610 syllabus, with attention to scientific accuracy, terminology and syllabus relevance. Participation may vary by guide.
Ms Yash
IGCSE Biology Teacher
10+ years teaching IGCSE Biology
Ms Prasanna
Biology Teacher
More than 9 years teaching Biology
Ms Phavytra
Biology Teacher
More than 11 years teaching Biology
Experience statements are published as supplied for this site. No examiner status, qualification or affiliation is implied unless it is separately documented.