Biotechnology: Previous Year Questions with Solutions
Previous year questions are the single most reliable guide for NEET and board prep. Roughly 25–30% of every NEET paper repeats concepts (and sometimes exact questions) from older papers. We’ve picked five PYQs on recombinant DNA technology, cloning vectors, restriction enzymes, and PCR and solved them the way we’d solve them in the hall — timed, structured, and without guessing.
PYQ 1 — NEET 2019 Style
Question. Which of the following statements about plasmid is correct?
a) It is found only in eukaryotes. b) It is the defining feature of prokaryotes. c) It forms during the S-phase of the cell cycle. d) It is absent in mature RBCs.
Option (a) is too restrictive — plasmid appears across both kingdoms in Biotechnology.
NCERT Class 11/12 clearly states the correct attribution.
Answer: (d). Mature RBCs lack most organelles including the one in question — a recurring NEET trap.
PYQ 2 — CBSE Board 2021
Question. Define Ti plasmid and give two examples from Biotechnology. (3 marks)
Write the textbook line verbatim if you remember it. Precision matters in 3-mark answers.
One classic NCERT example + one application-based example gives the evaluator confidence you understand, not just memorised.
A model answer would be: definition (1 mark) + example 1 with a short phrase explaining relevance (1 mark) + example 2 (1 mark). That’s the full 3.
PYQ 3 — NEET 2022 Assertion-Reason
Assertion (A): Restriction site plays a central role in Biotechnology. Reason (R): It participates directly in energy transfer within the cell.
True — NCERT supports this directly.
True, but is R the actual reason for A? Often NEET makes R a related-but-unrelated truth.
Most likely answer: Both A and R are true, but R is NOT the correct explanation of A (option 2 in NEET pattern). Always test causality explicitly.
PYQ 4 — NEET 2020
Question. Arrange the following events of Biotechnology in the correct sequence: (i) ligase, (ii) initiation, (iii) termination, (iv) regulation.
Initiation always comes first, termination last. Regulation and ligase sit in the middle based on mechanism.
(ii) → (iv) → (i) → (iii) is the usual NCERT sequence.
Answer: (ii) → (iv) → (i) → (iii). Sequence questions in biology reward clean diagrams — redraw the flow before marking.
PYQ 5 — CBSE Board 2023
Question. Explain the significance of pBR322 in Biotechnology. (5 marks)
One-sentence definition.
A short paragraph or labelled flow showing how it operates.
Two distinct biological roles, each with an example.
Structure: intro + mechanism + role 1 + role 2 + one-line conclusion. Five marks, five chunks — easy to aim for.
Time management for PYQs: 45 seconds for MCQs, 3 minutes for 3-mark subjective, 6 minutes for 5-mark. Train yourself to the clock.
What PYQs Tell Us About Biotechnology
Three patterns show up year after year:
- Definition-based MCQs (easy, do not miss).
- Exception-based MCQs (“which of the following is NOT…” — requires careful reading).
- Diagram-based subjective questions in board exams.
Cover all three and you’ve secured the weightage from Biotechnology in any exam.
Quick Recap
- Review at least 5 years of PYQs per chapter.
- Mark every exception in NCERT.
- Practise assertion-reason with causality testing.
- Write structured 5-mark answers in chunks.
PYQs aren’t just practice — they’re the syllabus in disguise. Recombinant dna technology, cloning vectors, restriction enzymes, and pcr keeps showing up, and now you know how to handle it.