What is the role of the guide RNA (gRNA) in CRISPR? 1. the gRNA opens the nucleus of a cell and allows the CRISPR CAS9 system into the nucleus.

2. the gRNA focuses the CRISPR CAS9 system on the specific sequence that needs to be cut.

3. the gRNA guides the CAS9 enzyme to the ends of the DNA molecule and lines up the appropriate bases.

4. the gRNA sequence is attached to the ends of introns so they can be removed by the CRISPR CAS9 system.