Suppose that a bacteriophage T strain carries a deletion mut

Suppose that a bacteriophage T strain carries a deletion mutation of two adjacent nucleotides, which of the following change might suppress this mutation?

ge T strain carries a deletion mutation of two adjacent nucleotides whi Suppose that a bacteriop O A. Another deletion of the next nucleotide. B. Insertion of one nucleotide downstream C. Insertion of two nucleotides downstream o D. Either A or C of the following change might suppress this mutation

Solution

Answer- Either A or C

When 2 adjacent nucleotide deleted the whole frame after the point of mutation become change which leads to defect in protein synthesis and different protein will be formed

To suppress this mutation another nucleotide is deleted which locate just next to already deleted nucleotid.in this way only one codon change while all other remain same as it is.

Example- 5\' CAT GAT CAT GAT CAT GAT CAT GAT...3\'

If GA deleted from second codon

Mutant genome

5\'CAT TCA TGA TCA TGA TCA TGA...3\'

Sequence gone out of frame.

If we delete one nucleotide next to deleted nucleotide i,e T

5\'CAT CAT GAT CAT GAT CAT GAT CAT...3\'

Only one amino acid changes in protein during translation which doesn\'t affect protein property.

IF two nucleotide inserted down stream in mutant frame

5\'CAT TCA TGA TCA TGA TCA TGA TCA TGA....3\'

GA inserted after second codon ( downstream to previous mutation site)

5\'CAT TCA GAT GAT CAT GAT CAT GAT CAT CAT ...3\'

In this way only few amino acid sequence change and reaming sequence revert a to normal.