Expert study guides, comprehensive exam structures, historical weightings, calculator methodologies, and common candidate mistakes for OCR A Level Biology A (H420).
読了時間 4 分更新日: 2026年6月21日
試験の概要
試験数
3
満点
270
制限時間
6時間
出題形式
3
試験
時間
配点
問題数
配点比率
出題形式
Biological processes
2時間 15分
100
51
37%
Multiple Choice Questions (MCQ), Structured Short Answer, Level of Response Essay
Biological diversity
2時間 15分
100
48
37%
Multiple Choice Questions (MCQ), Structured Short Answer, Level of Response Essay
Unified biology
1時間 30分
70
19
26%
Structured Short Answer, Level of Response Essay
評価段階
A*ABCDEU
電卓の規定
A scientific or graphical calculator that meets JCQ regulations may be used (some GCSE Mathematics and Science papers are non-calculator). Graphical calculators must be set to exam mode; you must clear any stored programs, notes or data before the exam, and the calculator must not be able to retrieve stored text or formulae.
過去問と採点基準にもとづいて作成（2022–2024）。
電卓プログラム
Graph: zeros, intersections & turning points
Graphical calculator / GDC (exam mode)
目的: Plot a function to read its roots (zeros), points of intersection, and maxima/minima.
使う場面: Checking solutions, sketching, or solving where an analytic method is hard.
手順
Graph the function(s) and use the built-in zero, intersect and maximum/minimum tools.
試験での注意: Allowed under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
Numerical equation solver
Graphical calculator / GDC (exam mode)
目的: Solve an equation or find a variable numerically when an algebraic route is long or implicit.
使う場面: Iterative or implicit equations, or to confirm an algebraic solution.
手順
Use the equation/zero solver, entering the equation and a sensible starting estimate.
試験での注意: Allowed under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
Numerical integration & differentiation
Graphical calculator / GDC (exam mode)
目的: Evaluate a definite integral \(\int_a^b f(x)\,dx\) or a gradient \(f'(x)\) at a point.
使う場面: Checking calculus answers, or where only a numerical value is needed.
手順
Use the GDC's numeric integral / derivative function with the limits or the point.
試験での注意: Allowed under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
Statistics & probability distributions
Graphical calculator / GDC (exam mode)
目的: 1-var/2-var statistics, linear regression, and cumulative binomial / normal / Poisson probabilities without tables.
使う場面: Statistics questions and hypothesis tests.
手順
Enter data in the statistics editor, or use the distribution menu (binomial cdf, normal cdf, …).
試験での注意: Allowed under JCQ rules, but you must still show your method — an unsupported calculator answer earns no method marks. Clear all stored programs, notes and data (graphical calculators in exam mode) before the exam.
よくあるミス
1high影響する配点: 3Ecosystems
Failing to calculate and plot frequency density when plotting histograms where class intervals are unequal.
回避方法: Always calculate frequency density (frequency divided by class width) for each interval when plotting histograms with variable category widths.
2medium影響する配点: 1Populations and sustainability
Omitting the negative sign in rates of change where a population or variable is declining.
回避方法: Double-check the direction of the trend. If the trend is downwards, ensure the rate value includes a negative sign.
3high影響する配点: 1Transport in plants
Suggesting that plant cutting procedures completely stop water loss rather than reduce it.
回避方法: Use conditional/relative language. State that the action 'reduces' or 'minimises' transpiration rather than stops it.
4medium影響する配点: 2Ecosystems
Using unspecific terms like 'nitrifying bacteria' when asked to describe nitrification.
回避方法: Name the specific genera: Nitrosomonas for converting ammonia to nitrites, and Nitrobacter for converting nitrites to nitrates.
5high影響する配点: 3Cell structure
Forgetting to convert units from millimeters to micrometers during microscope graticule calibration math.
回避方法: Convert micrometer scale measurements to the same base units (e.g., multiply mm by 1000 to get µm) before executing division steps.
6medium影響する配点: 2Cellular control
Stating that point mutations always modify the tertiary structure of proteins.
回避方法: Explain that due to the degeneracy of the genetic code, silent mutations can occur where the altered codon still codes for the same amino acid, leaving the protein unchanged.
7medium影響する配点: 1Transport in plants
Thinking that the Casparian strip acts as a barrier to the symplast pathway.
回避方法: Remember that the Casparian strip is a suberin barrier embedded in the cell walls, thus blocking the apoplast pathway and forcing water into the symplast pathway.