What is Cas9 protein that is often mentioned in news?
A
A molecular scissors used in targeted gene editing
Correct Answer
B
A biosensor used in the accurate detection of pathogens in patients
C
A gene that makes plants pest-resistant
D
A herbicidal substance synthesized in genetically modified crops
Explanation
Cas9 is a specialized protein that functions as "molecular scissors" to cut DNA at specific locations, allowing for precise genome engineering within the CRISPR-Cas9 system. While options like (c) describe traits found in genetically modified crops (such as the *Bt* gene), Cas9 is the enzymatic tool used to perform the editing rather than the trait-conferring gene itself. This question tests the core concept of modern biotechnology and the mechanisms of gene-editing technology.
BiotechnologyCRISPR-Cas9 gene editingCas9 proteinmolecular scissorstargeted gene editingbiosensorpathogenspest-resistant plantsherbicidal substanceCRISPR