Biology 0610 · syllabus 21
Cambridge IGCSE Biology 0610 — Biotechnology and genetic modification topical past papers
How bacteria, yeast and enzymes are used to make bread, biofuels, fruit juice and medicines, how fermenters work, and how organisms are genetically modified.
- Questions
- 304
- Years
- 2010–2026
- With mark scheme
- 99%
- Questions 2022–2026
- 115
Anyone can browse these pages. Opening the questions and their mark schemes takes a free Momentum account.
What Biotechnology and genetic modification covers
Biotechnology uses living organisms, mostly microorganisms, to make useful products. Bacteria are well suited because they reproduce quickly and can make complex molecules; Extended candidates add that using them raises few ethical concerns and that their plasmids make it easy to give them new genes. Yeast's anaerobic respiration is used in two ways: it produces ethanol for biofuels, and in bread-making its carbon dioxide makes the dough rise. Enzymes are used as well: pectinase breaks down the pectin in plant cell walls, releasing more juice from fruit and making it clearer, and biological washing powders contain enzymes that digest stains at lower temperatures.
Extended candidates describe production on an industrial scale. Lactase is used to make lactose-free milk, and fermenters grow bacteria and fungi in large numbers to make products such as insulin, penicillin and mycoprotein. Conditions inside must be controlled: the temperature, because respiration releases heat that could denature enzymes; the pH; the oxygen supply, for aerobic respiration; the supply of nutrients; and the removal of waste products. The vessel is also kept sterile so that no other microorganisms grow and contaminate the product.
Genetic modification alters an organism's genetic material by adding, removing or changing particular genes. Examples include bacteria given a human gene so that they make a human protein such as insulin, and crop plants given genes for resistance to herbicides or insect pests or for better nutritional value. Extended candidates outline the process: the human gene is cut out with a restriction enzyme, leaving sticky ends; a plasmid is cut with the same enzyme, leaving complementary sticky ends; DNA ligase joins them into a recombinant plasmid; and the plasmid is put into bacteria, which multiply and express the gene. They also weigh up the benefits and risks of genetically modified crops such as soya, maize and rice.
In the syllabus
The headings this topic has in the Cambridge International 2026–2028 syllabus, as the board prints them.
- 21 Biotechnology and genetic modification
- 21.1 Biotechnology and genetic modification
- 21.2 Biotechnology
- 21.3 Genetic modification
What you should be able to do
- Give the reasons bacteria suit biotechnology and genetic modification
- Explain how yeast's anaerobic respiration is used to make ethanol for fuel and to raise bread
- Explain what pectinase does in making fruit juice, and test how well a biological washing powder removes a stain
- Give examples of genetic modification in bacteria and in crop plants
- Describe how fermenters are used and why each condition inside them is controlled (Extended)
- Outline how a human gene is put into bacteria, and weigh up the benefits and risks of genetically modified crops (Extended)
Key ideas
- Yeast respiring anaerobically: glucose → alcohol + carbon dioxide; the ethanol is used as fuel, and the carbon dioxide makes bread rise
- Pectinase digests pectin in plant cell walls, so more juice is released and it is clearer
- Lactase breaks down lactose, the sugar in milk, so lactose-free milk can be made (Extended)
- Restriction enzymes cut DNA, leaving sticky ends; DNA ligase joins pieces of DNA; a recombinant plasmid carries the new gene (Extended)
- Fermenter conditions: temperature, pH, oxygen, nutrients and the removal of waste, in a sterile vessel (Extended)
How Biotechnology and genetic modification has been examined
From 2022 to 2026, Biotechnology and genetic modification was on Paper 4 · Theory (Extended) in 9 of 14 exam series, worth about 8% of that paper’s marks.
| Paper | Questions | Share of marks | Series |
|---|---|---|---|
| Paper 1 · Multiple Choice (Core) | 37 | 3% | 13 of 14 |
| Paper 2 · Multiple Choice (Extended) | 51 | 4% | 14 of 14 |
| Paper 3 · Theory (Core) | 13 | 5% | 8 of 14 |
| Paper 4 · Theory (Extended) | 14 | 8% | 9 of 14 |
Momentum’s own count, over the questions in its bank for these years: a series is one exam session, every zone included, and a question filed under two chapters counts in both. Median marks per question: 1.
Filed in Momentum under: Biotechnology and Genetic Engineering.
Mistakes that cost marks
- Saying the alcohol makes bread rise — bubbles of carbon dioxide from the yeast make the dough rise; the alcohol evaporates during baking
- Saying biological washing powders work best in very hot water — their enzymes denature at high temperatures; they are designed to work at lower temperatures, which also saves energy
- Treating genetic modification as a kind of selective breeding — genetic modification moves particular genes directly, even between species, while selective breeding crosses whole organisms over many generations
- Cutting the plasmid with a different restriction enzyme — the same enzyme must cut both pieces of DNA so that their sticky ends are complementary and can join (Extended)
- Forgetting that a fermenter needs cooling — the microorganisms' respiration releases heat, so the temperature must be held down, often with a water jacket (Extended)
Exam technique
- In enzyme investigations with fruit pulp or stained cloth, keep the mass of pulp or the size of the stain, the volume of enzyme and the temperature the same, and set up a control with boiled enzyme or water
- For the genetic modification process, write the steps in order and name the enzyme at each step: a restriction enzyme to cut, ligase to join (Extended)
- When discussing genetically modified crops, give at least one advantage and one disadvantage, tied to the crop or trait in the question (Extended)
- Link each fermenter condition to the biology: temperature and pH for enzyme activity, oxygen for aerobic respiration, sterility to stop contamination (Extended)
Practising in Momentum
- Every question in a chapter as one list, from every paper and year in the bank, newest first or shuffled.
- Each question turns over to its own part of the mark scheme, where the board published one.
- Narrow by paper, year, session, zone and marks, and star the questions worth keeping.
- Pick chapters, a number of questions and a time, and the exam builder draws a mock to sit and mark.
Past-paper questions and mark schemes are the copyright of Cambridge International. Momentum shows them to signed-in learners for revision and does not publish them on these pages.