✓ Board-verified
Biology · 2026 · 4 marks
Biotechnology : Principles and ProcessesProcesses of Recombinant DNA Technology4 marksUnderstandcase study
CBSE 2026 · Region 2 · Set 1 · Q29
Gene manipulation is a fast emerging science. It started with the development of recombinant DNA molecules. This technology which mostly involves…
Gene manipulation is a fast emerging science. It started with the development of recombinant DNA molecules. This technology which mostly involves cutting and pasting of desired DNA fragments is based on two most important discoveries in bacteria - presence of plasmid and restriction endonucleases. The science of r-DNA technology took birth when Cohen and Boyer ($\displaystyle 1973$) were able to produce a piece of gene containing foreign DNA introduced into plasmid of E.coli.
(a)
Name one core technique of biotechnology that alters the genetic material.
(b)
What is a plasmid ? Mention its importance in biotechnology.
(c)
Which gene was isolated by Cohen and Boyer and from which bacteria ?
OR
(c)
How is the action of exonuclease different from that of endonuclease ?
Marking-scheme solution
(a)
Genetic Engineering / Recombinant DNA Technology
(b)
• Plasmid is an autonomously replicating circular extra chromosomal DNA.
• It is used as a vector to transfer foreign genes into host cells.
(c)
Antibiotic resistant gene, Salmonella typhimurium
OR
(c)
Exonuclease: Remove the nucleotides from the ends of DNA strand.
Endonuclease: Make cuts at specific positions within DNA strand.
All Biotechnology : Principles and Processes questions2026 question paperNCERT solutions: Biotechnology : Principles and ProcessesPractice Biotechnology : Principles and Processes →
More from Biotechnology : Principles and Processes
- Given below is the restriction site of a restriction endonuclease Pst-I and the cleavage sites on a DNA molecule. 5^′ C-T-G-C-A ↓- G 3^′; 3^′ G ↑-…2023 · asked 2×
- The linking of the antibiotic resistance gene with the plasmid vector of Salmonella typhimurium by Stanley Cohen and Herbert Boyer was made possible…2024
- Which of the following is not required for PCR?2024
- With reference to the set-ups (A, B and C) given below, of the electrophoretic separation of a mixture of DNA fragments of varied lengths, answer the…2024
- (i) Given below is the schematic representation of the process of electrophoresis. Identify the alphabets representing the: (I) Anode end, and (II)…2026
- Assertion: The stirrer facilitates the even mixing of oxygen availability in a bioreactor. Reason (R): Stirred-tank bioreactors generally have a flat…2024
- The organism used in construction of the first artificial recombinant DNA by Cohen and Boyer in 1972 was:2023
- How is DNA isolated in purified form from a bacterial cell? OR Explain how human functional insulin was produced by using recombinant DNA (rDNA)…2025
CBSE Class 12 Biology past-paper question from the 2026 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.