What is species resistance?

• A. Immunity acquired through prior exposure to pathogens.
• B. Genetic characteristics that defend against pathogens.
• C. Antibody production by plasma cells.
• D. Behavior-based resistance to infection.

Answer: (B)

Species resistance is an inherited, genetic protection that a whole species has against certain pathogens. This kind of defense is built into the biology of the species, so individuals don’t rely on prior exposure or antibodies to stay safe, and it isn’t about behavior. For example, a pathogen may be unable to infect cells because the species lacks the necessary cell surface receptor, or the internal environment isn’t suitable for the pathogen to replicate. That genetic, species-wide protection is what this concept describes. The other ideas involve immunity gained after exposure, antibody production, or behavior, none of which are inherent, universal protections at the species level.