Chapter Overview & Weightage
- Marks in Boards: 6–10 marks (usually 1–2 questions + diagram/process)
- Repeated Topics: Recombinant DNA technology, tools (restriction enzymes, vectors, ligase), cloning process, PCR, gel electrophoresis, bioreactor, downstream processing.
- Difficulty: Moderate to high • Heavy on processes, diagrams (restriction digestion, cloning vector, PCR, gel electrophoresis) & steps.
- Trend (2021–2025): 1 diagram-based (5 marks) on cloning vector/PCR + 1 long answer (5 marks) on rDNA technology steps + MCQs on enzymes/vectors.
Most Important & Repeated Questions (2021–2025)
- Repeated 5–6 times: Explain the steps of recombinant DNA technology. Draw labelled diagram of cloning vector (pBR322). (5 marks)
- Repeated 4–5 times: Describe the process of PCR with diagram. Give applications. (5 marks)
- Repeated 4 times: What are restriction enzymes? Explain their role in rDNA technology with examples (EcoRI, HindIII). (3 marks)
- Repeated 3–4 times: Draw and label a typical cloning vector. Explain ori, selectable marker & cloning site. (5 marks)
- Repeated 3 times: Explain gel electrophoresis. How is it used in biotechnology? (3 marks)
- Repeated 3 times: What is a bioreactor? Describe its components & uses. (5 marks)
- Repeated 2–3 times: Explain downstream processing in biotechnology. (3 marks)
- Assertion-Reason (2023–2025): Assertion: Plasmids are good cloning vectors. Reason: They have ori & antibiotic resistance genes. (Both true, reason explains – repeated 2x)
Important Keywords & Concepts to Memorize
- Biotechnology, recombinant DNA, restriction enzymes (restriction endonucleases), ligase, vector (plasmid, bacteriophage), ori (origin of replication), selectable marker (antibiotic resistance), cloning site, insertional inactivation, PCR (polymerase chain reaction), Taq polymerase, denaturation, annealing, extension, gel electrophoresis (agarose), ethidium bromide, bioreactor (stirred-tank, sparged), downstream processing, competent cells, transformation, microinjection, gene gun, Ti plasmid, Agrobacterium tumefaciens, palindromic sequence, sticky ends, blunt ends, annealing.
Exam Strategy for Chapter 11 (2026 Boards)
- Focus: Diagrams (pBR322 vector, PCR cycle, gel electrophoresis) – practice 4 daily
- High-scoring: Recombinant DNA technology steps (5 marks) + labelled cloning vector
- Time: 8–10 minutes per 5-mark question (diagram + steps)
- Tip: Label 6–8 parts in every diagram (ori, resistance gene, cloning site) – neatness = full marks
- Repeated: Role of restriction enzymes & ligase (2–3 marks)
This is Chapter 11 complete PYQ analysis.
If you want Chapter 12 or any other chapter, just say the chapter number or name.