OSMT (Ontario Society of Medical Technologists) Practice Exam

Which cell is most likely to kill viruses and cancer cells?

1. Plasma cell

2. Cytotoxic T cell

3. Killer B cell

4. Suppressor B cell

The correct answer is: Cytotoxic T cell

The correct answer is Cytotoxic T cell because these cells play a crucial role in the immune response by directly attacking and killing infected or cancerous cells. Cytotoxic T cells are a type of T lymphocyte that can recognize specific antigens presented on the surface of infected or malignant cells and induce apoptosis (programmed cell death) in those cells. This ability to target and eliminate cells that harbor viruses or have become cancerous is vital for maintaining the body's defense against diseases. Plasma cells, on the other hand, are responsible for producing antibodies, which help to neutralize pathogens but do not directly kill infected or cancerous cells. Killer B cells, while they do produce antibodies, do not have the direct cytotoxic effect associated with T cells. Suppressor B cells are involved in regulating immune responses but do not play a direct role in killing viruses or tumor cells. Thus, Cytotoxic T cells are specifically equipped for the task of targeting and destroying compromised cells, making them the most likely candidates in this scenario.