Final answer:
Defensive proteins are produced by the immune system, and include antibodies and complement proteins which are part of the body's defense against pathogens
Step-by-step explanation:
Defensive proteins are a crucial component of the body's immune system. These proteins, including antibodies and complement proteins, are produced as a response to infections or the presence of foreign bodies. The immune system can be divided into two main types: the innate immune system, which responds quickly to pathogens but not specifically, and the adaptive immune system, which takes longer to respond but is highly specific and has memory for pathogens it has encountered before. Among the various defense mechanisms of the immune system is the production of antibodies by B cells after recognizing foreign antigens. Additionally, the complement system, consisting of proteins made in the liver, plays a role in both the innate and adaptive immune response against pathogens.