Which statement about innate resistance is supported by the definitions?

• A. Innate resistance can be due to age or breed, without prior exposure or immunization.
• B. Innate resistance requires vaccination
• C. Innate resistance is the same as acquired immunity
• D. Innate resistance depends on prior infection

Answer: (A)

Innate resistance is natural, non-specific protection that a host possesses independent of prior exposure or immunization. It reflects inherent factors such as age and genetic makeup, including breed or other heritable traits, that influence baseline susceptibility to infection.

Because innate defenses are present without a need for prior encounters, it makes sense that age or breed can contribute to different levels of innate resistance. Vaccination and prior infections drive adaptive, memory-based immunity, not the innate system, and acquired immunity is distinct from innate resistance. Therefore, the statement that innate resistance can be due to age or breed, without prior exposure or immunization, is the best description.