Question

First evidence for triplet genetic code was given by

• A. Crick
• B. Nirenberg and Matthaei
• C. Dr. H. G. Khorana
• D. Severo Ochoa

Hint:

Key contributions to remember:
Gamow = Proposed the triplet code theoretically.
Crick = Proved the triplet nature experimentally (via frameshift mutations).
Nirenberg & Matthaei = Deciphered the first codon.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The genetic code is the set of rules by which the sequence of nucleotides in DNA or RNA is translated into the sequence of amino acids in proteins.
A triplet code means that a sequence of three nucleotides specifies a single amino acid.

Step 2: Key Formula or Approach:
Recall the historical timeline of genetic code discoveries and specifically who provided the first direct experimental proof of its triplet nature.

Step 3: Detailed Explanation:
George Gamow theoretically proposed the triplet code.
Francis Crick and his colleagues provided the first experimental evidence for the triplet nature of the genetic code in 1961 using frameshift mutations in the T4 bacteriophage.
Nirenberg and Matthaei were the first to decipher a specific codon (UUU for Phenylalanine) using a cell-free system.
Dr. H. G. Khorana developed chemical methods to synthesize RNA molecules to further decode the dictionary.

Step 4: Final Answer:
Since Crick provided the first experimental evidence, option (A) is correct.