Higher Biology: the new single paper for 2027, the assignment and practice

The Higher Biology exam in 2027

The exam counts for 80% and the assignment for 20%. Until 2026 there were two papers: Paper 1 (25 multiple-choice marks in 40 minutes) and Paper 2 (95 marks in 2 hours 20 minutes). Qualifications Scotland merged and shortened them after a survey of learners and teachers. The new format is in the course specification valid from session 2026 to 2027; the content is unchanged.

The assignment: you research a topic, carry out an experiment or field work and write a report. It should take no more than 8 hours, with at most 2 hours to write the report under supervision, and Qualifications Scotland marks it.

What Higher Biology covers

• DNA and the genome: DNA structure and replication, gene expression, cellular differentiation, the genome, mutations, evolution and genomic sequencing.
• Metabolism and survival: metabolic pathways, cellular respiration, metabolic rate, conformers and regulators, surviving adverse conditions, and environmental and genetic control of metabolism.
• Sustainability and interdependence: food supply and plant productivity, plant and animal breeding, crop protection, animal welfare, symbiosis, social behaviour, and biodiversity and threats to it.

Higher Biology grade boundaries

In 2026, on the old format, out of 150 (120 marks over two papers, plus the assignment scaled to 30), an A needed 105, a B 89, a C 74 and a D 58. Of the 6,660 candidates, 32.7% got an A (course report 2026). The 2027 course is out of 125, so those numbers won't carry over. As a guide, the grading system aims for a C at about 50% and an A at about 70%.

Higher Biology practice questions

We wrote these for this guide. Higher Biology rewards precise terms, so use them.

1. DNA replication

Question: explain why one strand of DNA is replicated in fragments. Answer: DNA polymerase can only add nucleotides to the 3′ end of a growing strand. The two template strands run in opposite directions, so one new strand (the leading strand) is built continuously, while the other (the lagging strand) is built in short fragments that ligase joins together. See the steps in our guide to DNA replication.

2. Mutations

Question: why does inserting one nucleotide usually affect a protein more than substituting one? Answer: an insertion is a frameshift mutation: it changes every codon after it, so many amino acids change and the protein is usually non-functional. A substitution changes only one codon, so at most one amino acid changes, and sometimes none. Test yourself on mutation types in our Genetics and DNA course and press Mark.

3. Metabolic rate

Question: in a calorimeter, a small mammal gives off 1.2 kJ of heat in 10 minutes. Express its metabolic rate in kJ per hour. Answer: an hour is 6 lots of 10 minutes, so 1.2 × 6 = 7.2 kJ per hour. The 2026 report found few candidates managed a calorimeter calculation, so practise converting units of time.

4. Interpreting a field trial

Question: a new fertiliser raised a crop's yield from 4.0 to 5.2 tonnes per hectare. Find the percentage increase, and name one variable to control in the trial. Answer: (5.2 − 4.0) ÷ 4.0 × 100 = 30%. Control a variable such as the crop variety, plot size or watering, so any difference is down to the fertiliser.

5. Natural selection

Question: explain how natural selection increases the frequency of an allele. Answer: individuals with the allele are better suited to the environment, so they survive and reproduce more. They pass the allele on, so over generations its frequency in the population rises. Model it in the Natural Selection simulator.

Common Higher Biology mistakes

From the 2026 course report, few candidates managed these:

• Calorimeter calculations of metabolic rate.
• Selectable markers: explaining how a selective agent, such as an antibiotic, picks out bacteria that carry the marker gene and so the inserted gene.
• The Calvin cycle: explaining why the concentration of RuBP stays constant while the plant is in light (it's used and regenerated at the same rate).
• Data handling: conclusions that miss a change point in the data, and graphs with two y-axes.

Use a daily paper as a short timed prelim

Today's Higher Biology paper covers DNA replication, protein synthesis, enzymes, genetic diversity and classification, which overlap the DNA and the genome area. It also includes the cell cycle, gas exchange, mass transport, the immune system and biological molecules, which aren't in Higher Biology, and it doesn't cover metabolism and survival or sustainability and interdependence, or have a multiple-choice section. So use it for part of the course, alongside the official past papers (papers before 2027 are longer). For prelim dates, see our prelims guide.

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