OSMT (Ontario Society of Medical Technologists) Practice Exam

Which type of white blood cells recognize foreign antigens and produce antibodies?

1. Monocytes

2. Neutrophils

3. Lymphocytes

4. Eosinophils

The correct answer is: Lymphocytes

Lymphocytes are a critical component of the adaptive immune system and are specifically tasked with recognizing foreign antigens. Among the various subtypes of lymphocytes, B cells play a vital role in this process. When B cells encounter a foreign antigen, they activate and differentiate into plasma cells, which are responsible for producing antibodies. These antibodies are proteins that bind specifically to the antigens, helping to neutralize or eliminate the pathogens. Monocytes, while important in the immune response and capable of differentiating into macrophages and dendritic cells, do not produce antibodies directly. Neutrophils are the main type of phagocytic cells that respond to infections but are not involved in the antibody production process. Eosinophils primarily deal with parasitic infections and are more involved in allergic reactions than in the production of antibodies. Therefore, lymphocytes, particularly B cells, are essential for recognizing foreign antigens and the generation of antibodies, making them the correct answer.