WJEC A-level Biology: the four units, options, grades and 2027 dates

WJEC A-level Biology: the specification

WJEC GCE AS and A level Biology is a Welsh Government regulated qualification, first taught in 2015 (specification version 3, October 2023). It is not available to centres in England, where Eduqas runs a separate A level covered in our Eduqas A-level Biology guide. The AS can be taken alone, and practical work is compulsory: you keep a lab book of the specified practicals.

WJEC A-level Biology units

Every written paper has short and longer structured questions and one extended response. In Unit 4, Section B is one option chosen from three: Immunology and Disease, Human Musculoskeletal Anatomy, or Neurobiology and Behaviour. Dates are from WJEC's final summer 2027 timetable; see the WJEC A-level timetable 2027.

What each unit covers

• AS 1: biological compounds, cell structure and organisation, cell membranes and transport, enzymes, nucleic acids and their function, and how genetic information is copied.
• AS 2: evolutionary relationships and classification, adaptations for gas exchange, transport and nutrition.
• A2 3: the importance of ATP, photosynthesis, respiration, microbiology, population size and ecosystems, human impact on the environment, homeostasis and the kidney, and the nervous system.
• A2 4: sexual reproduction in humans and plants, inheritance, variation and evolution, applications of reproduction and genetics, and your option.

Worked examples in WJEC style

Hardy-Weinberg

In a population, 4% of individuals have a recessive condition. Using p² + 2pq + q² = 1, q² = 0.04, so:

So 32% of the population are carriers. The equation only applies when the population is large, mating is random, there is no migration or mutation, and no selection.

Chi-squared test

A monohybrid cross is expected to give a 3 : 1 ratio. Of 100 offspring, 78 show the dominant trait and 22 the recessive. The expected numbers are 75 and 25:

There is 1 degree of freedom (2 classes minus 1), and the critical value at the 5% level is 3.84. Because 0.48 is smaller, the difference is not significant, so the results fit a 3 : 1 ratio.

WJEC A-level Biology grades

Unit results become uniform marks and are added. The AS has 200 and the A level 500.

An A* needs an A overall (400 uniform marks) and at least 90% of the uniform marks for the A2 units, which is 270 out of 300. At AS the grades are A to E. A unit result is reported as a lower case letter a to e on the results slip, not on the certificate. See A-level grades explained.

Use the daily papers as short timed mocks for WJEC A-level Biology

Uni-Sine publishes a new free daily paper on each track: A-level Biology Year 1 and A-level Biology Year 2. It is a short timed mock: 8 questions worth 25 to 35 marks, marked instantly, with worked answers. It is not a full exam paper and it is not written by the exam board, so use it as a quick timed practice test alongside the board's own specimen and past papers.

• What it covers well: enzymes, membranes, nucleic acids, protein synthesis, gas exchange, transport, photosynthesis, respiration, homeostasis and the kidney, inheritance and Hardy-Weinberg, evolution and ecosystems, which line up with Units 1 to 4.
• What it does not cover: the three Unit 4 options as WJEC sets them, sexual reproduction in humans and plants, and the Unit 5 practical. Use WJEC papers for the extended response essay and the option questions.

One daily paper for recall, then a WJEC unit paper each week once you reach the A2 content.

Exam answers

Uni-Sine does not publish official answers, past paper answers or mark schemes from the exam board. The answers and a worked mark scheme for each daily paper come with that day's paper once it is marked, so you can see where every mark was won or lost.

Common mistakes in WJEC A-level Biology

• Writing a list instead of the extended response. Plan the essay with headings and link ideas.
• Forgetting degrees of freedom in a chi-squared test.
• Treating the option as optional revision. It is 20 marks of Unit 4.
• Using vague words. Name the enzyme, the membrane or the structure.

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