Which term best describes a highly precise type of genetic engineering that uses engineered nucleases to insert, delete, or replace DNA in an organism's genome?

• A. Gene editing
• B. Gene testing
• C. Stem cell research
• D. Immunizations

Answer: (A)

Precise genetic modification using engineered nucleases to insert, delete, or replace DNA in an organism's genome is called gene editing. Engineered nucleases such as CRISPR-Cas9, TALENs, and zinc finger nucleases act like molecular scissors that cut at specific DNA sequences. After the cut, the cell’s repair processes can be guided to insert new DNA, delete a segment, or replace it with a different sequence. This targeted approach achieves changes at exact locations in the genome, rather than broad or random alterations. That precision sets gene editing apart from gene testing, which only analyzes DNA for variants; stem cell research, which explores using stem cells; and immunizations, which are vaccines to prevent disease. So the term that fits is gene editing.