NCERT Class 12 Biology Biology: Chapter 9 — Biotechnology and Its Applications
This chapter, "Biotechnology and Its Applications," delves into the transformative impact of biotechnology on human life, particularly in health and food production. It highlights how modern biology, through biotechnology, has brought qualitative improvements. The chapter introduces the foundational principles and processes of biotechnology, referencing the groundbreaking work of Herbert Boyer and Stanley Cohen. Their discovery of restriction enzymes that cut DNA with 'sticky ends' and the manipulation of plasmids for DNA recombination and insertion into bacterial cells laid the groundwork for biotechnology. This breakthrough enabled bacteria to act as manufacturing plants for specific proteins, revolutionizing the field and its applications in improving human welfare and comfort. The chapter aims to provide insights into these core concepts and their practical uses.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 12 |
| Subject | Biology |
| Book | Biology |
| Chapter | Chapter 9 — Biotechnology and Its Applications |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 1 minute |
| Word count | 138 |
Learning outcomes
- Understand the historical development of biotechnology.
- Recognize the contributions of key scientists like Herbert Boyer and Stanley Cohen.
- Explain the significance of restriction enzymes and plasmids in genetic engineering.
- Appreciate the role of biotechnology in improving health and food production.
Vocabulary
| Word | Meaning |
|---|---|
| Biotechnology | The application of biological processes, organisms, or systems to manufacture products intended to improve the quality of human life. |
| Restriction enzymes | Enzymes that cut DNA at specific recognition nucleotide sequences known as restriction sites. |
| Sticky ends | Overhanging single-stranded ends of DNA produced by the action of certain restriction enzymes, which can readily anneal to complementary ends. |
| Plasmids | Small, circular, double-stranded DNA molecules that are separate from the chromosomal DNA and can replicate independently in bacterial cells. |
| DNA splicing | The process of cutting and joining DNA fragments, often used in genetic engineering. |
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Practice questions
- Who are the key scientists credited with founding the discipline of biotechnology? Answer: Herbert Boyer and Stanley Cohen are credited with founding the discipline of biotechnology.
- What property of restriction enzymes did Herbert Boyer discover? Answer: Herbert Boyer discovered that restriction enzymes could cut DNA strands in a particular fashion, leaving 'sticky ends'.
- What are plasmids? Answer: Plasmids are small, circular DNA molecules found in bacterial cells that can replicate independently.
- How did the work of Boyer and Cohen lead to the development of biotechnology? Answer: By combining Boyer's discovery of restriction enzymes with Cohen's method of manipulating plasmids, they could recombine DNA segments and insert them into bacterial cells, enabling these cells to produce specific proteins.
Practice MCQs
Q1. Which century saw the rise of biotechnology as a significant field?
Explanation: Biotechnology is described as a twentieth-century off-shoot of modern biology.
Q2. Herbert Boyer's research focused on which type of enzymes?
Explanation: Boyer studied restriction enzymes of the E. coli bacterium and their capability of cutting DNA.
Q3. What are 'sticky ends' in the context of DNA?
Explanation: Sticky ends are the result of restriction enzymes cutting DNA in a way that leaves short, single-stranded overhangs.
Q4. Stanley Cohen was known for his work with which genetic element?
Explanation: Cohen had been studying small ringlets of DNA called plasmids.
Q5. What role did bacterial cells play after the breakthrough by Boyer and Cohen?
Explanation: The DNA inserted into bacterial cells allowed them to act as manufacturing plants for specific proteins.
Frequently asked questions
What is biotechnology?
Biotechnology is a field that uses biological processes, organisms, or systems to manufacture products intended to improve human life, particularly in health and food production.
Who are considered the pioneers of modern biotechnology?
Herbert Boyer and Stanley Cohen are widely recognized for their foundational work that led to the establishment of biotechnology.
What significant discovery did Herbert Boyer make regarding DNA?
Herbert Boyer discovered that certain restriction enzymes could cut DNA strands precisely, leaving 'sticky ends' which facilitated DNA splicing.
What are plasmids and why are they important in biotechnology?
Plasmids are small, circular DNA molecules in bacteria that can replicate independently. They are crucial in biotechnology as vectors to carry and insert desired DNA segments into host cells.
How did Boyer and Cohen combine their discoveries?
They combined Boyer's restriction enzymes for cutting DNA with Cohen's methods for manipulating and reinserting plasmids into bacterial cells, enabling the creation of recombinant DNA.
What is the significance of inserting recombinant DNA into bacterial cells?
Once recombinant DNA is inserted into bacterial cells, these cells can act as 'manufacturing plants' to produce specific proteins or other desired products.
Related resources
Important topics
Topics covered
NCERT Class 12 Biology — Biology — Chapter 9 — Biotechnology and Its Applications. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.