Read the following and answer the question given below : Restriction e...
Restriction endonucleases are referred to as molecular or biological scissors because they can cleave both strands of DNA at specific sites. This property is crucial for genetic engineering applications where precise cuts are required to splice genes or insert new sequences into DNA.
Therefore, the correct answer to why restriction endonucleases are called molecular or biological scissors is:
2 they cleave one or both the strands of DNA
This answer reflects the ability of these enzymes to make cuts in double-stranded DNA, which is essential for their role in recombinant DNA technology.
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Read the following and answer the question given below : Restriction e...
Explanation:
Restriction Endonucleases:
- Restriction endonucleases are enzymes that cut DNA at specific recognition sites.
- They are found in bacteria and are part of the bacterial defense system against foreign DNA, such as viral DNA.
- Restriction endonucleases recognize specific DNA sequences and cleave the DNA at or near these sequences.
Types of Restriction Endonucleases:
- There are three types of restriction endonucleases: Type I, Type II, and Type III.
- Type I restriction endonucleases cut DNA at random sites far away from the recognition sequence.
- Type III restriction endonucleases cut DNA at random sites within a short distance from the recognition sequence.
- Type II restriction endonucleases cut DNA at specific sites within the recognition sequence.
Role in Recombinant DNA Technology:
- Recombinant DNA technology involves the manipulation of DNA molecules to create new combinations of genetic material.
- Type II restriction endonucleases are commonly used in recombinant DNA technology.
- They are used to cut DNA at specific sites, creating fragments that can be combined with other DNA fragments.
- This allows scientists to insert genes or specific DNA sequences into other organisms, creating genetically modified organisms.
Restriction Endonuclease EcoR I:
- EcoR I is a Type II restriction endonuclease that recognizes the base sequence GAATTC in DNA duplex.
- It cuts the DNA duplex between the G and A bases in the recognition sequence.
- The resulting fragments can then be used in various molecular biology techniques, such as cloning or DNA sequencing.
Why Restriction Endonucleases are called Molecular or Biological Scissors:
- Restriction endonucleases are called molecular or biological scissors because they cleave one or both strands of DNA.
- They cut the DNA at specific recognition sites, creating fragments that can be manipulated in various molecular biology techniques.
- This ability to cleave DNA at specific points allows scientists to precisely manipulate DNA and create new combinations of genetic material.
Therefore, the correct answer is option 'B': they cleave one or both strands of DNA.
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