Advances in biotechnology, especially regarding genetic testing and gene therapy, now allow for the screening and possible
treatment of many genetic disorders. During gene therapy, for example, specific gene sequences are inserted into an individual's
cells and tissues to replace a defective or mutant allele.
What have scientists found to be the most efficient and effective way to insert new sequences into an individual?
A. Scientists irradiate genes so that they can be absorbed through the skin.
B.
Scientists inject DNA strands into cells using a syringe.
C. Scientists have created genetically altered foods that release DNA during digestion.
D. Scientists use viruses to insert specific gene sequences.