Question

Consider the CRISPR-Cas9 system for gene editing. When introduced into a eukaryotic cell, the Cas9 makes double stranded breaks in the DNA that are repaired by the eukaryotic cell. The ____________directs Cas9 to the correct target gene(s). ________________ is an efficient eukaryotic repair system, but often results in mistakes like insertions or deletions. _________________ only operates during G1 and S, operates rarely, but can be used to specifically substitute bases or even replace an entire gene.

a. PAM; Non-homologous end joining; Homology directed repair

b. PAM; Homology directed repair; Non-homologous end joining

c. gRNA; Non-homologous end joining; Homology directed repair

d. gRNA; Homology directed repair; Non-homologous end joining

e. Zinc finger nuclease; Non-homologous end joining; Homology directed repair

Answer 1