Question

Choose the correct answer from the alternatives given :
Read the following statements.
(i) One codon codes for only one amino acid.
(ii) Some amino acids are coded by more than one codon.
(iii) The, sequence of triplet nitrogenous bases in DNA or mRNA corresponds to the amino acid sequence in the polypeptide chain.
Give suitable terms for the characteristics of genetic code as per the above statements.

• A. Degeneracy - (i), Colinearity - (ii), Unambiguous - (iii)
• B. Degeneracy - (iii) , Colinearity - (ii) , Unambiguous - (i)
• C. Degeneracy - (ii) , Colinearity - (iii) , Unambiguous - (i)
• D. Degeneracy - (i) , Colinearity (ii) , Unambiguous - (iii)

Answer 1

The correct option is C Degeneracy - (ii) , Colinearity - (iii) , Unambiguous - (i)

As there are 64 combination of the base pairs A,G,U and C possible that are required to code for the 20 major amino acids more than one code can give rise to a single type of amino acid. This is called degeneracy and is exhibited as the multiplicity of three-base pair codon combinations that specify an amino acid. The genetic code is a three-letter (triplet) code defining the transfer of the information from nucleic acids to proteins. Codon is a successive string of three nucleotide and this corresponds to the amino acid sequence in the polypeptide chain. This property of the genetic code is called Colinearity. Even though one amino acid can be coded by different codes, a particular code can give rise to only to a specific amino acid and this is the unambiguous nature of the genetic code. Each codon specifies one amino acid only.

So, the correct option is 'Degeneracy - (ii) , Colinearity - (iii) , Unambiguous - (i)'.