NCERT Class 12 Biotechnology Biotechnology: Chapter 4 — Applications of Recombinant DNA Technology
This chapter introduces students to the revolutionary applications of Recombinant DNA (rDNA) technology. It covers key areas such as DNA fingerprinting, the development of transgenic organisms, gene therapy, recombinant vaccines, and the production of therapeutic agents like monoclonal antibodies, insulin, and growth hormone. The chapter details DNA fingerprinting, explaining how variations in non-coding DNA regions, specifically Variable Number Tandem Repeats (VNTRs), are used to identify individuals and establish relatedness. It highlights the significance of these inherited variations in paternity testing and other forensic applications. The text emphasizes how rDNA technology provides solutions to numerous problems, impacting diagnostics, treatment, and the production of essential biological molecules, thereby enhancing human life and advancing medical science.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 12 |
| Subject | Biotechnology |
| Book | Biotechnology |
| Chapter | Chapter 4 — Applications of Recombinant DNA Technology |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 3 minutes |
| Word count | 479 |
Learning outcomes
- Understand the significance and various applications of Recombinant DNA technology.
- Learn the principles and methodology of DNA fingerprinting.
- Identify the characteristics and uses of transgenic organisms.
- Comprehend the concept and potential of gene therapy.
- Recognize the production and importance of recombinant vaccines and therapeutic agents.
Vocabulary
| Word | Meaning |
|---|---|
| Recombinant DNA | DNA formed by combining genetic material from different sources. |
| DNA Fingerprinting | A technique used to identify individuals based on their unique DNA patterns. |
| Transgenic Organism | An organism whose genome has been altered by the transfer of genes from another species. |
| Gene Therapy | A technique that uses genes to treat or prevent disease. |
| Polymorphism | The occurrence of different forms of alleles within a population. |
| VNTR | Variable Number Tandem Repeats; short DNA sequences repeated in tandem, showing high polymorphism. |
| STR | Short Tandem Repeats; a type of VNTR with shorter repeat units. |
| Nitrogenous Bases | Components of DNA: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T). |
| Human Genome | The complete set of genetic material present in a human cell. |
| Paternity Testing | Using DNA analysis to determine if a man is the biological father of a child. |
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Practice questions
- What is the primary basis for DNA fingerprinting? Answer: The variations in DNA sequences, particularly VNTRs, which are inherited and show high polymorphism.
- Who developed the technique of DNA fingerprinting and when? Answer: Sir Alec Jeffreys developed DNA fingerprinting in 1984.
- What are VNTRs and STRs? Answer: VNTRs (Variable Number Tandem Repeats) are short DNA sequences repeated in tandem, showing high polymorphism. STRs (Short Tandem Repeats) are a subdivision of VNTRs with shorter repeat units (1-9 bp).
- Why is DNA fingerprinting useful in paternity testing? Answer: Because the polymorphisms in VNTRs are inheritable from parents to offspring, allowing comparison to confirm biological relatedness.
Practice MCQs
Q1. What percentage of the human genome is identical among humans?
Explanation: Approximately 99.9% of the human genome is the same across individuals, with variations occurring in the remaining 0.1%.
Q2. VNTRs are commonly subdivided into which two principal families?
Explanation: VNTRs are typically classified into microsatellites (1-9 bp repeats) and minisatellites (10-100 bp repeats).
Q3. The technique of DNA fingerprinting was developed by:
Explanation: Sir Alec Jeffreys, a British geneticist, developed the DNA fingerprinting technique in 1984.
Q4. What does the 'T' represent in the DNA bases A, G, C, and T?
Explanation: The four nitrogenous bases in DNA are Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).
Q5. Which regions of an individual's genome are primarily used in DNA fingerprinting?
Explanation: DNA fingerprinting relies on variations found in the non-coding regions of the genome, such as VNTRs.
Frequently asked questions
What is Recombinant DNA (rDNA) technology?
rDNA technology involves combining DNA from different sources to create new genetic combinations, leading to revolutionary applications in various fields.
How does DNA fingerprinting work?
DNA fingerprinting analyzes unique patterns of short DNA sequences (like VNTRs) in an individual's genome to establish identity or relatedness.
What are VNTRs and why are they important for DNA fingerprinting?
VNTRs are variable regions in non-coding DNA that repeat in tandem. Their high degree of polymorphism (variation) makes them ideal markers for DNA fingerprinting.
Can DNA fingerprinting be used for paternity testing?
Yes, because VNTRs are inherited from parents, DNA fingerprinting can compare a child's DNA profile with that of a potential father to confirm paternity.
What are some other applications of Recombinant DNA technology mentioned in the chapter?
Other applications include developing transgenic organisms, gene therapy, creating recombinant vaccines, and producing therapeutic agents like insulin.
What is the significance of the 0.1% variation in the human genome?
This 0.1% variation in the human genome is responsible for the uniqueness of each individual and forms the basis for techniques like DNA fingerprinting.
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NCERT Class 12 Biotechnology — Biotechnology — Chapter 4 — Applications of Recombinant DNA Technology. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.