Define "genetic engineering."

Genetic engineering refers to the direct manipulation of an organism's genes using biotechnology. This process involves altering the genetic material—DNA or RNA—of an organism to achieve desired traits or characteristics. Techniques used in genetic engineering may include CRISPR, gene cloning, and recombinant DNA technology. This field has applications in medicine, agriculture, and research, allowing for advancements such as producing insulin for diabetes management, developing pest-resistant crops, and studying gene functions.

In contrast, the other options focus on different aspects of biological study. The study of proteins in organisms highlights proteomics, while the indirect study of ecological systems pertains to ecology rather than genetic manipulation. Observing gene expression in native organisms is an important part of genetics research but does not directly involve altering genes. Thus, the focus on manipulating genes in genetic engineering sets it apart as a distinct and significant scientific discipline.