Given the question: Answer the following question given this paragraph: 42.3 | Antibodies By the end of this section, you will be able to: Explain cross-reactivity Describe the structure and function of antibodies Discuss antibody production An antibody, also known as an immunoglobulin (Ig), is a protein that is produced by plasma cells after stimulation by an antigen. Antibodies are the functional basis of humoral immunity. Antibodies occur in the blood, in gastric and mucus secretions, and in breast milk. Antibodies in these bodily fluids can bind pathogens and mark them for destruction by phagocytes before they can infect cells. Q: What protein is produced when a plasma cell is stimulated by antigens? Choices: - collagen - dystrophin - keratin - immunoglobulin A:
The answer is:
immunoglobulin