Match List - I with List - II.

  Choose the correct answer from the options given below:

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

The correct answer is Option (2) - (A)-(III), (B)-(IV), (C)-(I), (D)-(II)

The construction of the first recombinant DNA emerged from the possibility of linking a gene encoding antibiotic resistance with a native plasmid of Salmonella typhimurium.

The cutting of DNA at specific locations became possible with the discovery of the so-called ‘molecular scissors’– restriction enzymes. Restriction enzymes are part of a larger category of enzymes known as nucleases. Exonucleases and endonucleases are the two types. Endonucleases make cuts at specified places within the DNA, whereas exonucleases remove nucleotides off the ends.

DNA ligase (joining or sealing enzymes) is an enzyme, that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.  Thus, they help in sealing gaps in DNA fragments. Therefore, they act as a molecular glue.

The blue-white screen is a screening technique that allows for the rapid and convenient detection of recombinant bacteria . This technique is based on the insertional inactivation of the β-galactosidase gene. Cells transformed with vector containing the recombinant DNA contain an inactive form of the β-galactosidase gene and hence produce white colonies. cells transformed with non-recombinant plasmid i.e. only the vector, have an active β-galactosidase gene and thus produce blue colonies.