Which statement is true about the two primate species most used?

• A. Rhesus and Cynomolgus
• B. Marmoset and Squirrel monkey
• C. Baboon and Gibbon
• D. Chimpanzee and Gorilla

Answer: (A)

The main idea is that rhesus macaques and cynomolgus macaques are the two primate species most commonly used in research. This pairing is favored because macaques are large enough to perform a wide range of procedures with relative ease, yet manageable in standard facilities. Their physiology and immune system closely resemble humans, making them highly valuable for toxicology, infectious disease studies, vaccine development, neuroscience, and translational research. There is a long history of data, established husbandry and veterinary care protocols, well-understood anesthesia and analgesia practices, and extensive breeding programs and resources, which together create a predictable and efficient model for many disciplines. While other primates like marmosets and squirrel monkeys are used in specialized areas, and larger primates such as baboons, gibbons, chimpanzees, and gorillas face particular ethical, regulatory, or logistical constraints, the macaque pair remains the most widely utilized in regulated labs.