Blood proteins that attack and inactivate bacteria and viruses that cause infection are called:

• A. Cytokines
• B. Enzymes
• C. Antibodies
• D. Hormones

Answer: (C)

Verified step by step guidance

1. Understand the role of blood proteins in the immune system: Blood contains various proteins that help defend the body against pathogens such as bacteria and viruses.
2. Review the definitions of the given options: Cytokines are signaling molecules that regulate immune responses; enzymes catalyze biochemical reactions; hormones regulate physiological processes; antibodies specifically recognize and bind to antigens on pathogens.
3. Identify which blood proteins directly attack and inactivate bacteria and viruses: Antibodies are specialized proteins produced by B cells that bind to specific antigens on pathogens, neutralizing them or marking them for destruction.
4. Recognize that antibodies are part of the adaptive immune response and are crucial for targeting specific infectious agents.
5. Conclude that among the options, antibodies are the blood proteins responsible for attacking and inactivating bacteria and viruses.