# Biotechnology: Principles and Processes Notes | SwaVid Biotechnology: Principles and Processes, NCERT Class 12 Biology: notes with key ideas, key terms, common mistakes and 3 quick checks with worked answers. Canonical: https://www.swavid.com/cbse/class-12/biology/chapter/biotechnology-principles-and-processes Source: https://www.swavid.com/cbse/class-12/biology/chapter/biotechnology-principles-and-processes # Biotechnology: Principles and Processes ## Key terms ## Key ideas ## Common mistakes ## Quick checks ## Keep going ## Questions parents ask ## Class 12 Biology on SwaVid ### Principles of biotechnology ### Restriction enzymes ### Cloning vectors ### Competent host and transformation ### Polymerase chain reaction ### Bioreactors and downstream processing ### Next chapter ### Related chapter ### All chapters SwaVid › CBSE › Class 12 › Biology › Biotechnology: Principles and Processes Notes written by SwaVid from the NCERT textbook. Class 12 Biology, Chapter 9. Key ideas, formulas and common mistakes. CBSE prints 12 marks for Unit IX, not for this chapter alone. Short answer. This chapter introduces the core principles of genetic engineering and the tools required to create recombinant DNA. Students learn the step-by-step processes of isolating DNA, cutting, cloning, and culturing cells on a large scale in bioreactors. Source: NCERT Biology (Reprint 2026-27) , Chapter 9, Biotechnology: Principles and Processes Biotechnology rests on two core techniques: genetic engineering and bioprocess engineering. Genetic engineering alters the genetic material of an organism to change its phenotype, while bioprocess engineering maintains sterile conditions to grow desired microbes in large quantities. Restriction endonucleases cut DNA molecules at specific palindromic recognition sequences. They generate either sticky ends or blunt ends, which allow foreign DNA fragments to join with vector DNA using DNA ligase. Vectors are DNA molecules used to carry foreign genetic material into another cell. Essential features of a vector include an origin of replication (ori), selectable markers to identify transformants, and specific cloning sites. Bacterial cells must be made competent to take up plasmid DNA, usually by treatment with divalent cations like calcium and heat shock. Alternate methods for introducing recombinant DNA include micro-injection into animal cells and biolistics or gene gun in plants. PCR amplifies a specific segment of DNA in vitro through repeated cycles of denaturation, primer annealing, and extension. The reaction uses a thermostable DNA polymerase called Taq polymerase isolated from Thermus aquaticus. Bioreactors provide optimum growth conditions such as temperature, pH, substrate, and oxygen to produce target proteins at large volumes. Downstream processing covers the subsequent separation and purification steps required before marketing the finished product. Try each question first. Then tap it to see the answer. Number of molecules produced after n cycles follows the relation 2ⁿ. For n = 4 cycles starting from 1 template, calculate 2⁴. 2⁴ = 16. 16 molecules Divalent cations like Ca²⁺ increase the efficiency with which DNA enters the bacterium through cell wall pores. Subsequent heat shock at 42 °C followed by chilling on ice forces the recombinant DNA into the bacterial host. It alters cell wall permeability, enabling DNA uptake through transient pores. Agarose gel acts as a sieve where DNA fragments separate strictly according to their size. Smaller fragments experience less resistance from the matrix compared to larger fragments. The 200 base pair fragment is smaller than the 1200 base pair fragment. The 200 base pair fragment, because smaller fragments travel farther through the gel matrix. Biotechnology and its Applications . Molecular Basis of Inheritance . The 13 chapters of Class 12 Biology . CBSE does not give marks to one chapter. It prints 12 marks for Unit IX, Biotechnology and its Applications, which includes Biotechnology: Principles and Processes. No. They are written by SwaVid from the NCERT textbook. The CBSE curriculum is the reference for what is assessed. Biotechnology and its Applications. SwaVid is an AI tutor for Indian students in Classes 6 to 12. It finds the earlier ideas a child missed, then teaches today’s chapter. Start free to see how it works. - Ch 9 NCERT book - 12 marks, Unit IX - 3 quick checks - Confusing the functions of exonucleases and endonucleases . Remember that exonucleases remove nucleotides from the terminal ends of DNA, while endonucleases make cuts at specific points within the DNA strand. - Thinking both recombinant and non-recombinant cells turn blue in insertional inactivation of beta-galactosidase . Recombinant colonies lack functional beta-galactosidase and remain white, while non-recombinant colonies have an active enzyme that turns the chromogenic substrate blue. - Assuming DNA fragments in agarose gel move towards the negative electrode . DNA fragments carry a negative charge due to phosphate groups, so they migrate toward the positive anode during gel electrophoresis. - Using different restriction enzymes to cut the foreign DNA and the vector . Both foreign DNA and the vector must be cleaved with the same restriction enzyme so that their sticky ends have complementary matching sequences. ## Key Links - [CBSE](https://www.swavid.com/cbse) - [Class 12](https://www.swavid.com/cbse/class-12) - [Biology](https://www.swavid.com/cbse/class-12/biology/chapters) - [Start free →](https://www.swavid.com/signup) - [All 13 chapters](https://www.swavid.com/cbse/class-12/biology/chapters) - [NCERT Biology (Reprint 2026-27)](https://ncert.nic.in/textbook.php) - [Open notes](https://www.swavid.com/cbse/class-12/biology/chapter/biotechnology-and-its-applications) - [Open notes](https://www.swavid.com/cbse/class-12/biology/chapter/molecular-basis-of-inheritance) - [Class 12 Biology](https://www.swavid.com/cbse/class-12/biology/chapters) - [Start free →](https://www.swavid.com/signup)