Curriculum
Science Grade IX
Biotechnology
School Revise · Grade 9 · Advanced Science (Optional) · Chapter 10
Engineering Life: Miracles in Biotechnology
Science at Advanced Level, Class 9. This optional chapter shows how we put living things to work, from Bt crops and golden rice to making human insulin in bacteria, and how fermenters grow microbes at scale.
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What this chapter is about
For thousands of years people have used microbes to make curd, bread and more. Today we can move a single gene from one organism to another. In this chapter we meet modern biotechnology, its uses in farming and medicine, and the fermenter that grows microbes on a large scale.
1. Traditional and modern biotechnology
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Biotechnology biotechnology is the careful use of living things, or their parts, to make products useful to people Traditional biotechnology uses natural microbes, as in making curd or bread. Modern biotechnology, also called genetic engineering or recombinant DNA technology, cuts a chosen gene from one organism and pastes it into another. In real life: The curd set at home overnight is traditional biotechnology; the insulin that treats diabetes is modern biotechnology at work. |
2. Biotechnology in farming
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Bt crops and golden rice a gene from the soil bacterium Bacillus thuringiensis makes crops make their own insecticide; added genes make golden rice rich in vitamin A In Bt cotton the added gene makes the plant produce a protein toxic to certain pests but harmless to us, cutting the need for chemical sprays. Golden rice carries genes that make beta carotene, which our bodies turn into vitamin A. In real life: Golden rice was made to fight vitamin A deficiency, a cause of childhood blindness in regions where rice is the main food. |
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Worked example 1 Question. How does Bt cotton protect itself from bollworms?
Answer: The added Bt gene makes the plant produce a toxin that kills the pest that feeds on it. |
3. Making insulin, and the fermenter
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Insulin by recombinant DNA the human insulin gene is joined to a bacterial plasmid, put into bacteria, and the bacteria then make human insulin The gene is cut out with restriction enzymes, joined to a cut plasmid by DNA ligase to make a recombinant plasmid, and placed into E. coli. Grown in a fermenter, the bacteria produce insulin, which is then purified. In real life: Before this, insulin came from animal pancreases; now bacteria make pure human insulin cheaply for millions of people with diabetes. |
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The fermenter (bioreactor) a large vessel that grows microbes under controlled conditions to make a product A stirrer mixes the broth, a sparger adds air for the microbes, a cooling jacket carries away heat, and pH sensors keep the broth balanced. It must be sterilised first so no unwanted microbe spoils the culture. In real life: Antibiotics, enzymes for washing powders and vaccines are all grown in fermenters just like this, in tanks holding thousands of litres. |
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Worked example 2 Question. Why must a fermenter be sterilised before use?
Answer: So that no unwanted microbe contaminates and spoils the rich culture. |
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Worked example 3 Question. Why are bacteria good tools for making a product like insulin?
Answer: Because they grow fast, need little space, and their DNA is easily given new instructions. |
Practise with the interactive
Try this chapter hands on: change the values and watch the result update live and animate. The interactive opens right here in the lesson.
Practice set A, multiple choice
1. Modern biotechnology differs from traditional in that it …
Deliberately moves a chosen gene from one organism to another, rather than relying only on natural microbial action.
2. The Bt gene comes from …
The soil bacterium Bacillus thuringiensis, and makes a protein toxic to certain insect pests but harmless to us.
3. Human insulin is now made by …
Bacteria carrying the human insulin gene on a recombinant plasmid, grown in a fermenter.
4. In a fermenter, the sparger …
Adds air to the broth so the microbes can respire, while the stirrer mixes and the cooling jacket removes heat.
Practice set B, short answer
1. Why was golden rice developed?
To fight vitamin A deficiency, a cause of blindness in children in regions where rice is the staple food; it carries genes that make beta carotene, which the body turns into vitamin A.
2. Put the insulin steps in order: into E. coli, cut the gene, join to plasmid, grow in a fermenter.
| 1 | Cut the gene. take the human insulin gene using restriction enzymes. |
| 2 | Join to plasmid. use DNA ligase to make a recombinant plasmid. |
| 3 | Into E. coli. transform the bacterium with it. |
| 4 | Grow in a fermenter. the bacteria multiply and make insulin. |
3. Give one use each of biotechnology in medicine, farming and the environment.
Medicine: making insulin. Farming: Bt crops that resist pests. Environment: bioremediation, where microbes break down oil spills and other pollutants.
Quick summary
| Idea | The idea |
| Biotechnology | Using living things to make useful products. |
| Modern kind | Moves a gene between organisms. |
| Bt crops | Make their own pest toxin. |
| Golden rice | Rich in vitamin A. |
| Insulin | Made by bacteria via recombinant DNA. |
| Fermenter | Grows microbes at scale. |
| Open the Virtual Lab |
These free Grade 9 Advanced Science notes explain biotechnology, Bt crops, golden rice, insulin production and industrial fermenters, with clear step by step worked examples and labelled diagrams for every student using the optional Advanced Level book.
© 2026 School Revise. All rights reserved. This lesson is original content written by School Revise, aligned to the CBSE Class 9 Science at Advanced Level (Optional) syllabus. Unauthorised copying, reproduction or redistribution is not permitted. Curriculum names are used only to indicate alignment.
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