Choose the correct answer from the options given below:

1. (A)-(IV), (B)-(II), (C)-(I), (D)-(III)
2. (A)-(II), (B)-(IV), (C)-(I), (D)-(III)
3. (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
4. (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

   This matching question links molecular biology milestones: nucleic acid to Miescher, bacterial transformation to Griffith, one gene-one enzyme hypothesis to Beadle and Tatum, and restriction enzymes to Arber, Smith, and Nathans.​

   Question Breakdown

   Match List I terms to List II scientists. Key concepts from early genetics and biotech for exams like GATE Life Sciences.​

   • (A) Nucleic Acid: Discovery event.

   • (B) Bacterial Transformation: Genetic transfer process.

   • (C) One gene one enzyme hypothesis: Gene function theory.

   • (D) Restriction enzymes: DNA cutting tools.​

   Correct Matches

   (A) Nucleic Acid – (II) Johann Friedrich Miescher

   Miescher isolated “nuclein” (DNA) in 1869 from white blood cell nuclei in pus bandages, identifying its phosphorus-rich nature from cell nuclei.

   (B) Bacterial Transformation – (IV) Frederick Griffith

   Griffith’s 1928 experiment showed heat-killed virulent pneumococci transformed avirulent bacteria via a “transforming principle” (later DNA).​

   (C) One gene one enzyme hypothesis – (I) George Beadle and E. Tatum

   Beadle and Tatum’s 1941 Neurospora crassa mutants proved one gene codes for one enzyme, foundational to molecular genetics.​

   (D) Restriction enzymes – (III) W. Arber, H. Smith and D. Nathans

   These Nobel winners (1978) discovered restriction endonucleases: Arber (modification), Smith (cleavage sites), Nathans (use on DNA).​

   Option Analysis

   • (1) (A)-(IV), (B)-(II), (C)-(I), (D)-(III): Wrong; A not Griffith (transformation), B not Miescher.​

   • (2) (A)-(II), (B)-(IV), (C)-(I), (D)-(III): Correct; all matches align with historical facts.

   • (3) (A)-(I), (B)-(II), (C)-(III), (D)-(IV): Wrong; A not Beadle/Tatum, B not Miescher.​

   • (4) (A)-(III), (B)-(I), (C)-(IV), (D)-(II): Wrong; A not restriction enzymes.​

   Correct Answer: (2)

   Milestone Timeline

   Event	Scientist(s)	Year	Impact
   Nucleic Acid	Miescher ​	1869	Identified DNA as nuclear substance
   Bacterial Transformation	Griffith	1928	Proved DNA as genetic material
   One gene-one enzyme	Beadle & Tatum	1941	Gene-protein link
   Restriction enzymes	Arber, Smith, Nathans	1960s-70s	Enabled recombinant DNA ​

   These form the backbone of genetics, from discovery to tools for biotech. Perfect for exam prep on historical contributions.