Which components are described as playing roles in the immune system?

Which components are described as playing roles in the immune system?

• A. Hemoglobin and myoglobin.
• B. Collagen and elastin.
• C. Complement and Toll-like receptors.
• D. Actin and myosin.

Answer: (C)

The main idea is that immune system components include proteins and receptors that actively recognize pathogens and drive defense. The complement system consists of circulating proteins that, when activated, tag microbes for destruction (opsonization), recruit inflammatory cells, and can form pores in pathogen membranes to lyse them. Toll-like receptors are a family of pattern recognition receptors on innate immune cells that detect conserved microbial molecules; their engagement sets off signaling cascades that produce cytokines and inflammatory responses, helping to coordinate both innate and adaptive immunity. In contrast, hemoglobin and myoglobin primarily carry oxygen; collagen and elastin provide structural support in tissues; actin and myosin are involved in cell movement and muscle contraction. These do not play direct, active roles in immune recognition or effector functions.

The main idea is that immune system components include proteins and receptors that actively recognize pathogens and drive defense. The complement system consists of circulating proteins that, when activated, tag microbes for destruction (opsonization), recruit inflammatory cells, and can form pores in pathogen membranes to lyse them. Toll-like receptors are a family of pattern recognition receptors on innate immune cells that detect conserved microbial molecules; their engagement sets off signaling cascades that produce cytokines and inflammatory responses, helping to coordinate both innate and adaptive immunity. In contrast, hemoglobin and myoglobin primarily carry oxygen; collagen and elastin provide structural support in tissues; actin and myosin are involved in cell movement and muscle contraction. These do not play direct, active roles in immune recognition or effector functions.