Cambridge IGCSE Biology 0610 · Topic 21
Biotechnology and Genetic Modification
Biotechnology uses living organisms, or products made by them, to manufacture things people want — yeast for bread and fuel, enzymes for juice and laundry, bacteria and fungi grown at industrial scale in fermenters. Genetic modification is something narrower sitting inside that broader field: a technique that edits an organism’s genetic material directly, gene by gene, rather than simply putting an unmodified organism to work. Keeping that distinction straight is most of what this chapter is actually testing.
Cambridge splits this into three connected sections. 21.1 asks why bacteria specifically are so useful for biotechnology and genetic modification — not because they’re small or convenient, but because of two named properties at Core level and two more at Supplement. 21.2 covers the biotechnology itself: yeast respiring anaerobically for biofuel and bread, enzymes doing specific industrial jobs in fruit juice, washing powders and lactose-free milk, and fermenters keeping bacteria or fungi growing under controlled conditions at scale. 21.3 moves to genetic modification proper — what it means, how it differs from selective breeding, the required example contexts, the bacterial gene-transfer process at Supplement level, and how to evaluate a genetically modified crop’s benefits and risks without sliding into a blanket “GM is good” or “GM is bad” claim.
Marks in this chapter tend to disappear in a specific way: a student names the right idea — “bacteria are used because they’re small,” “GM crops are bad for the environment” — without the mechanism underneath it. An examiner already agrees with the general direction of those statements; what earns the mark is the reasoning connecting a specific property, enzyme, gene or trait to its specific, biological consequence. The pages below are built around exactly that connective tissue.
What’s in this chapter
| Page | Level | What it covers |
|---|---|---|
| Why bacteria are used in biotechnology | Core + Supplement | Rapid reproduction and complex-molecule synthesis at Core level, then plasmids and the ethical-concerns qualifier at Supplement. |
| Yeast in biofuel and bread-making | Core | One anaerobic reaction, two industries — why the ethanol matters for biofuel and the carbon dioxide matters for bread. |
| Enzymes in biotechnology: pectinase and washing powders | Core | Pectinase and juice yield, biological detergent enzymes and stains — and the temperature/pH data Paper 6 likes to test here. |
| Lactase and lactose-free milk | Supplement | How treating milk with lactase, rather than removing sugar, produces milk that people with lactose intolerance can digest. |
| Fermenters and controlled conditions | Supplement | Insulin, mycoprotein and penicillin, and the five named conditions that keep a fermenter producing them efficiently. |
| Genetic modification: definition and examples | Core | What genetic modification actually is, how it differs from selective breeding, and the four required example contexts. |
| The process of genetic modification | Supplement | Restriction enzymes, sticky ends, DNA ligase and recombinant plasmids — the exact ordered sequence Cambridge expects. |
| Evaluating GM crops | Supplement | Why a strong answer traces one named trait to one specific consequence, rather than reaching for a ready-made verdict. |
Core or Supplement?
Three pages here are Core, so every candidate needs them regardless of tier: why bacteria are useful (its Core half), yeast in biofuel and bread-making, enzymes in biotechnology, and genetic modification’s definition and examples — that’s four Core pages in total once you count the Core half of the bacteria page separately from its Supplement half. The remaining content — plasmids and ethical concerns, lactase, fermenters, the genetic-modification process, and evaluating GM crops — is Supplement only, required for the Extended paper and not for Core-only candidates. If you’re unsure which tier you’re sitting, it’s worth checking before investing time in the Supplement pages, since none of the Core content depends on them.