Prelims 2019 · Science and Technology · Question 49
What is Cas9 protein that is often mentioned in news?
Answer
A molecular scissors used in targeted gene editing
- (a) A molecular scissors used in targeted gene editing — Correct. Cas9 is an enzyme used in the CRISPR-Cas9 system to cut DNA at specific sites, so it is called a molecular scissor.
- (b) A biosensor used in the accurate detection of pathogens in patients — Incorrect. CRISPR-based diagnostics exist, but Cas9 itself is primarily known for gene editing, not as a biosensor.
- (c) A gene that makes plants pest-resistant — Incorrect. Cas9 is a protein/enzyme, not a gene conferring pest resistance.
- (d) A herbicidal substance synthesized in genetically modified crops — Incorrect. Cas9 is not a herbicide or a chemical synthesized in GM crops; it is a DNA-cutting protein.
Answer: (a)