Match List-I with List-II
| List-I | List-II |
|---|---|
| Scientists | Discoveries |
| (A) Frederick Griffith | (I) Genetic Code |
| (B) Francois Jacob and Jacques Monod | (II) Semi-conservative mode of DNA replication |
| (C) Har Gobind Khorana | (III) Transformation |
| (D) Meselson and Stahl | (IV) Lac operon |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
(A) Frederick Griffith — this matches (III) Transformation. In 1928, with Streptococcus pneumoniae and mice, he found that heat-killed S strain changed living R strain into the virulent form.
(B) Francois Jacob and Jacques Monod — this matches (IV) Lac operon. They were the first to explain a regulated transcription unit, the lac operon of E. coli, which is switched on by lactose.
(C) Har Gobind Khorana — this matches (I) Genetic Code. His chemical method of making RNA with known base sequences helped to work out which codon stands for which amino acid.
(D) Meselson and Stahl — this matches (II) Semi-conservative mode of DNA replication. Growing E. coli first on 15N and then on 14N, they showed that each new DNA keeps one old strand.