Molecular Basis of Inheritance NEET PYQs (1988–2026)

Solved Molecular Basis of Inheritance PYQs

3 recent questions with answers. The full set of 226 is free to practise.

1. NEET 2026EasyGene expression regulation (lac operon)
   Q1

   In the lac operon, the z gene codes for

   • Apermease
   • Btransacetylase
   • Cbeta-galactosidase
   • Dthe repressor of lac operon

   Show answer & solution

   Correct answer: (C)

   z gene codes for beta-galactosidase.
2. NEET 2026HardTranscription and post-transcriptional modifications
   Q2

   Which of the following statements are correct with reference to a
   
   transcription unit?
   
   A. A transcription unit in DNA is defined primarily by three regions: promoter, structural gene and terminator.
   
   B. The promoter is said to be located towards the 5'-end of the structural gene.
   
   C. The promoter is a DNA sequence that provides binding site for RNA polymerase.
   
   D. The promoter defines the template and coding strands.
   
   E. The terminator is located towards the 3'-end of the coding strand and it defines the end of the process of transcription.
   
   Choose the correct answer from the options given below:

   • AA, B, C and D only
   • BA, C, D and E only
   • CB, C, D and E only
   • DA, B, C, D and E

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   Correct answer: (D)

   All statements A to E are correct.
3. NEET 2026MediumDNA fingerprinting
   Q3

   Arrange the following steps of DNA fingerprinting in a correct sequence.
   
   A. Isolation of DNA and its digestion by restriction endonucleases.
   
   B. Hybridisation using a labelled VNTR probe.
   
   C. Transferring of separated DNA fragments to synthetic membranes.
   
   D. Detection of hybridised DNA fragments by autoradiography.
   
   E. Separation of DNA fragments by electrophoresis.
   
   Choose the correct answer from the options given below:

   • AA, B, D, C, E
   • BA, D, B, E, C
   • CA, E, C, B, D
   • DA, E, B, C, D

   Show answer & solution

   Correct answer: (C)

   Correct sequence: Isolation & digestion (A) → Electrophoresis (E) → Southern blotting (C) → Hybridisation with probe (B) → Autoradiography (D). So A, E, C, B, D.

Topic-wise question count

Where NEET has asked from Molecular Basis of Inheritance, most frequent first.

• DNA structure and packaging63
• Genetic code and translation52
• Transcription and post-transcriptional modifications44
• Gene expression regulation (lac operon)34
• DNA replication mechanism19
• DNA fingerprinting8
• Human genome project6

Year-wise Molecular Basis of Inheritance questions in NEET

Number of questions from this chapter in each year's paper(s).