Which of the following is a common application of genetic engineering?

Developing insulin-producing bacteria for diabetes treatment is a notable application of genetic engineering because it harnesses biotechnology to create a viable solution for a significant health issue. By inserting the human gene responsible for insulin production into bacteria, scientists enable these microorganisms to produce human insulin efficiently. This process not only provides a sustainable source of insulin for diabetic patients but also overcomes the limitations of traditional insulin extraction methods that were previously reliant on animal sources. This application has transformed diabetes management and has become a pivotal example of how genetic engineering can directly improve human health.

In contrast, creating natural habitats for endangered species, cloning extinct plants, and increasing biodiversity in ecosystems involve ecological or conservation efforts that do not primarily utilize the principles of genetic engineering. These activities might enhance environmental sustainability or species conservation, but they do not illustrate the direct manipulation of genetic material characteristic of genetic engineering as effectively as the development of insulin-producing bacteria does.