Question

A foreign DNA and plasmid were cut with two different restriction endonucleases. DNA ligase was then added to join the sticky ends of the DNA fragments. However the recombinant plasmid could not be formed. To rectify the mistake in the procedure one has to (A) Cut only the plasmid with restriction enzyme (B) Cut only the foreign DNA with restriction enzyme (C) Not use a plamid Cut the foreign DNA and plasmid with same the restriction enzyme​

Answer 1

Answer:

Restriction enzymes are found in bacteria and they have some biological role (explained below), but we are exploiting it in our way to use in experiment.

Biological role of restriction enzymes in bacteria: when restriction enzyme is present in a given bacterium, such bacterium can prevent (restrict) the growth of certain bacterial viruses (bacteriophages) and this is the reason also to call it as RESTRICTION enzymes. in this way it is the defensive enzyme that protects the host bacterial DNA from the DNA genome of foreign organism (bacteriophage) by specifically inactivating the invading bacteriophage DNA by digestion

Answer 2

Answer:

Cut the foreign DNA and plasmid with same the restriction enzyme​