Question

Shown below is a nucleotide sequence and the genetic code. 

5' - ATGCGTAGACTCGTA - 3' 

(a) Identify the protein sequence formed by this sequence. 

(b) Draw the tRNA molecule for the third codon with its polarity labelled. Give a reason to support the polarity identified. 

(b) The first guanine base in the nucleotide sequence changes to cytosine. Identify the type of mutation caused by this change. 

(c) Will the mutated sequence form an mRNA and protein? Justify. 

Answer 1

(a) TYR ALA SER GLU HIS

(b) Correct drawing with anticodon 3' -AGA - 5'

Reason: The mRNA sequence is translated in the 5' to 3' direction so the anticodon has to be in the 3' to 5' direction

(c) point mutation

(d)  mRNA will be formed

protein will not be formed

The first codon is a stop codon due to which translation will not happen