Microbiology Practice Exam

The adaptive immune response is characterized by its specificity and memory, allowing the immune system to effectively respond to particular pathogens. T lymphocytes and B lymphocytes play complementary roles in this process.

T lymphocytes, also known as T cells, are crucial for cell-mediated immunity. They recognize and respond to antigens presented by infected or altered cells. Helper T cells enhance the immune response by activating other immune cells, while cytotoxic T cells directly kill infected or cancerous cells.

B lymphocytes, or B cells, are responsible for humoral immunity. They produce antibodies that specifically target pathogens and toxins in the bloodstream and extracellular spaces. When activated, B cells can differentiate into plasma cells, which secrete antibodies, or memory B cells, which provide long-term immunity against previously encountered pathogens.

The cooperation between T and B lymphocytes is essential for a robust adaptive immune response. T cells can assist B cells in producing a more effective and longer-lasting antibody response, while B cells can present antigens to T cells, facilitating a more coordinated immune response.

Natural killer cells do not play a direct role in the adaptive immune response. Instead, they are part of the innate immune system and provide rapid responses to viral-infected cells and tumor formation. While important in the