What is the Cas9 protein that is often mentioned in news?

1. A molecular scissors used in targeted gene editing
2. A biosensor used in the accurate detection of pathogens in patients
3. A gene that makes plants pest-resistant
4. A herbicidal substance synthesized in genetically modified crops

Explanation

Option (a) is correct

• Cas9 is a protein associated with the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) system, which is a technology for gene editing. It acts as a pair of “molecular scissors” that can precisely cut DNA at specific locations. CRISPR-Cas9 is a technology that allows the modification, addition, or removal of specific DNA sequences, changing genome portions.

Answer: (a) A molecular scissors used in targeted gene editing; Difficulty Level: Easy