Paper 2 · recombinant DNA technology
In recombinant DNA technology, both the DNA containing the required gene and the vector (e.g. plasmid) DNA must be cut at specific recognition sequences into fragments before the gene can be inserted into the vector. Which type of enzyme cuts DNA in this way?
Model answer
restriction endonuclease
Also accepted: restriction enzyme, restriction endonucleases, restriction enzymes
Explanation: Restriction endonucleases recognise specific short DNA sequences and cut the DNA at those points, producing restriction fragments. Using the same restriction enzyme on both the donor DNA and the plasmid produces complementary cut ends, so the isolated gene can be inserted into the cut vector.
Derived from ZIMSEC Biology Paper 2, June 2016, Q3
