National 5 Biology grade boundaries 2025: A, B, C, D marks

National 5 Biology grade boundaries 2025

The table is the Biology row of the National 5 sheet in the SQA's Grade boundaries 2025 (release 25GB, 5 August 2025); the grade counts are from the SQA's 2025 course report.

An A took 68.8% of the marks, a C 49.6% and a D exactly 40%. The National 5 Biology guide has the course content.

What the 125 marks are made of

In 2025 the course was a 100-mark question paper and an assignment. Section 1 was 25 multiple-choice marks and Section 2 was 75 marks of written answers, in 2 hours 30 minutes. The 20-mark assignment is scaled to 25, so the course total is 125 and the weights are 80% and 20%. The marks and timings come from the improving assessment paper, which gives them as the arrangements before the shorter 2027 paper.

The assignment is a report on an investigation in which you collect data and write up the results under supervision. The 2025 report said the assignment performed as expected, and the 2026 report says it performed as intended.

How many candidates got each grade in 2025

Fewer than three in ten candidates got an A, 6,352 or 28.8%, and 16.6%, 3,673 candidates, got No Award. C and D were each close to a fifth of candidates, 18.8% and 17.7%. Entries were 22,092, a small fall from 22,346.

Turning a mark into a grade

A candidate gets 18 on Section 1 and 52 on Section 2, so 70 out of 100, and 16 out of 20 on the assignment, which becomes 20 out of 25. That is 90 in all, above the A line of 86 and 15 below the upper A at 105. A candidate with 52 on the paper and 12 on the assignment gets 52 + 15 = 67, which is a C and 7 marks below the B line at 74.

B follows from A and C: with A at 86 and C at 62, the gap is 24, so B = 62 + ⌊49 ÷ 4⌋ = 62 + 12 = 74. The D boundary is 62 − ⌈47 ÷ 4⌉ = 62 − 12 = 50.

2025 against earlier years

Against 2024 (A 86, B 72, C 58, D 44) the A line did not move, B went up 2, C up 4 and D up 6, while the upper A came down from 106 to 105. In 2023 the course was marked out of 100 and the A was 77, which is a very high 77%, while 2022's A was 61%. These swings show how far the boundaries can move when assessments change. In 2019 the A was 84 of 125, 67.2%.

What the SQA said about the 2025 papers

The report says the question paper performed as intended and was fair and balanced, and that this was taken into account when setting the boundaries. The assignment performed as expected. It also says some candidates could improve their knowledge of basic biology and definitions, that markers highlighted literacy skills and knowledge of experimental set-up, and that some candidates had limited exposure to practical work.

Specific marks were lost on data and definitions. Most candidates did not say which potato cylinder would gain the most mass in sucrose solutions (Section 1, question 2), many could not calculate an average monthly increase or a percentage increase from a graph (14, 18), and many gave a generic definition of diffusion when asked why potassium moved out of seaweed (2(a)(i)). Most did not know the ultrastructure of a bacterial cell (1(a)(i)) or what a gene is (4(a)(i)), and nearly all did not say how an investigation would be changed (3(a)(iv)), with many just repeating it.

What the 2025 numbers mean for you

The lost marks are about definitions, graph skills and experimental design, not rare topics. Learn the definitions in the course specification word for word, practise percentage increase and averages from graphs, and for any experiment say what you would change, not that you would repeat it. The Cell Simulator helps with transport questions.

For the next series, see National 5 Biology grade boundaries 2026. For all courses, SQA grade boundaries 2025.

Check yourself with today's paper

Sit today's National 5 Biology paper, a short timed paper of 8 questions and 25 to 35 marks written by us, with no assignment. Divide your mark: 21 out of 30 is 70%, above the A share of 68.8%, and 15 out of 30 is 50%, just above the C share of 49.6%.

Read next

Scotland · National 5National 5 Biology grade boundaries 2026: A, B, C, D marksNational 5 Biology grade boundaries 2026 from Qualifications Scotland: unchanged at A 86, B 74, C 62 and D 50 of 125, with 33.2% getting an A.