Question

Recombinant DNA molecule can be created normally by cutting the vector DNA and source DNA respectively with:

• A. Hind II, Hind II
• B. Hind II, Alu I
• C. Hind II, EcoR I
• D. Hind II, BamHI

Answer 1

The Correct Option is A

To create a recombinant DNA molecule, both the vector DNA and the source (foreign) DNA need to be cut with the same restriction enzyme to ensure that the ends are compatible for ligation.

Let us evaluate the given options:

1. Hind II, Hind II: Using the same restriction enzyme, Hind II, to cut both vector and source DNA will produce complementary sticky ends that are perfectly compatible, facilitating the ligation process to form recombinant DNA. This is the correct approach.
2. Hind II, Alu I: These are different restriction enzymes that cut at different recognition sites. Using different enzymes like Hind II and Alu I would create non-compatible ends, making it difficult to ligate the DNA fragments.
3. Hind II, EcoR I: Similarly, Hind II and EcoR I have different recognition sites, leading to incompatibility in the ends, and thus, they would not facilitate forming recombinant DNA.
4. Hind II, BamHI: Different enzymes again mean different cutting sites, leading to incompatible ends for ligation.

The correct option is the first one: Hind II, Hind II because using the same enzyme ensures that the cut ends are cohesive and can be ligated to form a stable recombinant DNA molecule.