Question

If the bacterial DNA sequence is Leu Met Att Gal Bio, which of the genes can be transferred via specialized transduction?

(a) Leu and Met

(b) Met, Att and Gal

(c) Gal and Bio

(d) Met and Gal only

This question was addressed to me during an internship interview.

This is a very interesting question from Gene Mapping in Bacteria by Transduction in division Genomics : The Mapping and Sequencing of Genomes of Cytogenetics

Answer 1

Right option is (d) Met and Gal only

For explanation: Att site is merely necessary for incorporation of the virus. In specialized transduction the sites directly beside the attachment point of the virus can be mistakenly excised with the part of viral gene. Here this phenomenon will occur only in case of Met and Gal.