The cutting of DNA at specific locations became possible with the discovery of -
- Restriction enzymes
- Selectable markers
- Probes
- Ligases
Answer
(1) Restriction enzymes
Solution
As per NCERT, the cutting of DNA at specific locations became possible with the discovery of the so-called 'molecular scissors' – restriction enzymes.
⇒ Each restriction endonuclease recognises a specific palindromic base sequence and cuts the DNA there; ligases only join DNA fragments.
Answer: (1)