What is a major function of immunoglobulins?

Immunoglobulins, also known as antibodies, play a crucial role in the immune system, and one of their major functions is to neutralize toxic substances, including pathogens such as viruses and bacteria. When an immunoglobulin recognizes an antigen, it can bind to it, preventing the pathogen from entering or damaging host cells. This binding not only neutralizes the toxin or pathogen but also marks it for destruction by other immune cells.

The neutralization process is essential for protecting the body from infections and diseases. For example, immunoglobulins can neutralize bacterial toxins or block viral infection by preventing viruses from attaching to and penetrating host cells. This capability is fundamental to the adaptive immune response, allowing for a more refined and effective defense against a wide array of harmful agents.

In contrast, the other options do not accurately represent the primary functions of immunoglobulins. Hormone secretion is performed by endocrine glands, adhering to cell surfaces is typically associated with adhesion molecules, and clotting is largely a function of platelets and specific proteins in plasma rather than immunoglobulins. So, the major role of immunoglobulins in neutralizing toxic substances is indeed a vital component of the immune system's response to threats.