Answer:
knowledge of the sequence product
Step-by-step explanation:
A gene knockout is a technique used in molecular genetics to deactivate target genes in an organism in order to study their functions by reverse genetics (i.e., gene loss). Knockouts are generated by different methods including, for example, homologous recombination or site-specific nucleases (zinc-fingers, TALENS, CRISPR/Cas9). These techniques require to know a priori the sequence of each gene to be knocked out in order to target desired mutations. In the last years, the CRISPR/Cas9 tool has gained attention to knockout genes of interest because it is a genome editing system that can be easily used for deletion or insertion of bases.