Gene therapy is primarily used to address which of the following?

Gene therapy is designed to treat or prevent diseases by altering the genes inside a patient's cells. The primary focus of gene therapy is on inherited genetic disorders, which arise from mutations or abnormalities in the genes that can be passed down through generations. By targeting these specific genetic issues, gene therapy aims to correct or replace defective genes to alleviate the symptoms or even cure the disorder altogether.

Inherited genetic disorders cover a broad range of conditions, such as cystic fibrosis, hemophilia, and certain types of muscular dystrophy. In these cases, the approach may involve adding a healthy copy of a gene that is not functioning properly due to a mutation. This gene modification can lead to improved health outcomes and enhance the quality of life for affected individuals.

In contrast, the other options focus on broader concepts that do not align with the specific goals of gene therapy. Gene variation between species pertains to evolutionary biology rather than therapeutic interventions. Physical traits of an organism can be influenced by a range of factors, including environmental interactions, rather than solely through gene therapy. Evolutionary changes in species involve long-term processes of natural selection and adaptation, which are not the focus of individual-level gene therapy aimed at correcting genetic disorders.