Question

Genetic engineering is possible, because

• A. we can cut DNA at specific sites by endonucleases like DNAase
• B. restriction endonucleases purified from bacteria can be used in vitro
• C. the phenomenon of transduction in bacteria is well understood
• D. we can see DNA by electron microscope.

Answer 1

The Correct Option is B

Genetic engineering is possible because all organisms are based on the same genetic code. DNases which act on specific positions or sequences on the DNA are called as restriction endonucleases. The sequences which are recognised by the restriction endonucleases or restriction enzymes (RE) are called as recognition sequences restriction sites. These sequences are palindromic sequences. Different restriction enzymes present in different bacteria can recognize different or same restriction sites but they will cut at two different points within the restriction site. No two restriction enzymes from a single bacterium will cut at the same restriction site.