What is Cas9 protein that is often mentioned in news?

Correct Option: A molecular scissors used in targeted gene editing

Explanation:

Cas9 (CRISPR-associated protein 9) is an enzyme that acts as a pair of "molecular scissors" capable of cutting strands of DNA at specific, targeted locations within a genome.

Here is a breakdown of how it works and why it is significant:

1. Targeted Gene Editing (CRISPR-Cas9): CRISPR-Cas9 is a revolutionary gene-editing technology derived from a naturally occurring defense system in bacteria. Bacteria use it to detect and destroy foreign viral DNA.

2. Mechanism: The Cas9 enzyme relies on a small piece of RNA (guide RNA) that acts as a homing device. It directs Cas9 to a precise site in the DNA sequence. Once positioned, Cas9 cuts both strands of the DNA molecule.

3. Editing & Modification: After Cas9 makes the cut, scientists can use the cell's natural DNA repair machinery to add, delete, or alter specific gene sequences, making it a pivotal tool in biotechnology, genetics, and medicine.