Question

In genetic engineering, it is necessary to cut DNA out of bacteria and eukaryotes to insert the human insulin gene into a bacteria. Select the correct statement.

• A. Two different restriction enzymes so that the pieces wont reanneal.
• B. The same restriction enzyme so that both pieces will have the same sticky ends.
• C. Methylated bacterial DNA so that only some of it will be spliced.
• D. Two different ligases to reanneal the DNA.
• E. A hot water bath at 55 degrees centigrade so that the reaction will happen faster.

Answer 1

Answer: (B)

The same restriction enzyme so that both pieces will have the same sticky ends.

Insulin production includes isolation of donor DNA and formation of rDNA carrying the insulin gene followed by production of copies of rDNA which is then introduced in the recipient. For the purpose, donor DNA and vector DNA are cut with same restriction enzymes. The same restriction enzyme cuts the DNA at specific sites, produces uniform DNA fragments with sticky or blunts ends that are easily ligated with other DNA strands, a requisite for creating rDNA. Thus, the correct answer is option B.