Breeding and Biotechnology — Class 10 Science (Samacheer Kalvi)
TN State Board (Samacheer Kalvi) Class 10 Science, Biology — Chapter 20. Improving crops and livestock, and the tools of modern biotechnology.
1. About this chapter
This chapter covers plant and animal breeding, agricultural revolutions, and biotechnology — genetic engineering, GMOs and DNA fingerprinting.
2. Breeding
- Plant breeding: improving crops for higher yield, disease resistance and quality, by selection and hybridisation (crossing two varieties).
- Animal breeding: improving livestock through selective breeding (inbreeding, out-breeding, cross-breeding).
- Revolutions: Green Revolution (more food grains), White Revolution (milk), Blue Revolution (fisheries).
3. Biotechnology
- Biotechnology: the use of living organisms or their parts to make useful products.
- Genetic engineering / recombinant DNA technology: inserting a desired gene into an organism to give it a new trait.
- GMOs (genetically modified organisms): e.g., Bt cotton (pest-resistant).
- DNA fingerprinting: identifies individuals from their unique DNA — used in forensics and parentage tests.
4. Applications
Biotechnology gives insulin, vaccines, antibiotics, disease-resistant crops, and tools for medicine, agriculture and forensics.
5. Common mistakes
- Mistake: Confusing hybridisation with genetic engineering. Fix: Hybridisation crosses whole organisms; genetic engineering transfers a specific gene.
- Mistake: Mixing up the revolutions. Fix: Green = food grains, White = milk, Blue = fish.
- Mistake: Thinking DNA fingerprinting needs the whole genome to match. Fix: It compares specific unique DNA regions between samples.
6. Practice (book-back style)
- Define plant breeding and name two methods.
- What is the Green Revolution?
- What is genetic engineering?
- Give one example of a GMO.
- State two applications of DNA fingerprinting.
7. Answer key
- Improving crops for better yield/quality; selection and hybridisation.
- The large increase in food-grain production through high-yielding varieties and modern farming.
- Inserting a desired gene into an organism to give it a new, useful trait (recombinant DNA technology).
- Bt cotton (pest-resistant).
- Forensic identification and parentage (paternity) testing.
8. Quick revision
- Biology Ch 20 · breeding and biotechnology.
- Plant breeding: selection, hybridisation; animal breeding: selective breeding.
- Revolutions: Green (grains), White (milk), Blue (fish).
- Genetic engineering = transfer a specific gene (recombinant DNA); GMO e.g. Bt cotton.
- DNA fingerprinting: forensics and parentage; biotech gives insulin, vaccines.
