Question

Which of the following options are correct in the case of Restriction endonuclease?
A. It is used for in-vitro DNA synthesis
B. Used in genetic engineering
C. Cleaves DNA at specific sites
D. Both B and C

Answer 1

Hint: Restriction endonucleases are a type of enzyme that recognizes a specific DNA sequence. This specific DNA sequence is called a restriction site. The principal biological function of restriction endonuclease is the protection of the host genome against foreign DNA, in particular, bacteriophage DNA. The enzyme after identifying the site cleaves the DNA adjacent to that particular site.

Complete step by step answer:
A restriction enzyme is a specific type of enzyme that cleaves/cuts DNA into fragments at or near a specific site within the DNA molecules. These sites are known as restriction sites. Cleaving enzymes are broadly classified into two types based on their site of action,
A. Exonuclease – These types of enzymes cut DNA at the terminal end sites.
B. Endonuclease- Intermediate sites of DNA are cut by the use of this type of enzyme.
Restriction endonuclease belongs to the broader group of endonuclease enzymes. As the name suggests, it restricts a particular site inside the DNA by recognizing it, and then it cuts the specific site.
From the given options, it is clear that restriction endonucleases cleave DNA at specific sites. This property of restriction endonuclease is used in genetic engineering. So, both options B and option C are correct in this scenario.
Hence, the correct answer is option (D).

Note: Restriction endonuclease enzymes identify the origin of incoming DNA and destroy it. If the DNA is recognised as a foreign threat. Restriction endonucleases recognise specific sequences in the incoming DNA and digest the DNA into fragments. Hence, Restriction endonucleases are synthesised by bacteria as a part of their defence mechanism.