What are genetically altered rodents used for in research?

• A. To mimic human diseases and observe disease progression.
• B. To study plant genetics.
• C. To replace all other animals.
• D. To train as service animals.

Answer: (A)

Genetically altered rodents are used to model human diseases and observe disease progression. By engineering mice or rats to carry human disease genes or to lose specific gene functions, researchers create living systems that mirror aspects of human conditions. This allows study of how a disease starts, how it evolves, and how different genes influence its course, as well as how potential therapies affect outcomes over time. The advantages of rodents include short lifespans, rapid breeding, and a rich toolkit for genetic manipulation, which makes it feasible to explore disease mechanisms and test treatments before moving to human studies. Techniques such as introducing mutations, knocking out genes, or inserting human gene sequences using CRISPR or other methods enable modeling of cancers, neurodegenerative disorders, metabolic diseases, and more. While these models provide valuable insights, they’re not perfect replicas of human disease, so findings are carefully interpreted and validated with additional models and human data. Other options don’t fit: plants are studied for plant genetics, replacing all animals isn’t the primary goal of using these models, and service-animal training is unrelated to research modeling.