Assertion : A change in nitrogen bass at the third position of a codon causes change in the expression of the codon.
Reason : A codon is mostly read by all the three nitrogen bases.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. if both assertion and reason are false.

Answer

d

Explanation

(d) : According to the Wobble hypothesis , only the first two position of a triplet codon on mRNA have a precise pairing with the bases of the tRNA anticodon . The pairing of the third position bases of the codon may be ambiguous and varies according to the nucleotide present in this position. Thus ,a single tRNA type is able to recognise two or more codons differing only in the third base. The same is called wobble position.