Question

Write a note on lymphocytes.

Hint:

Recall the two lymphocyte types: B cells (antibodies) matured in bone marrow, T cells (cell attack) matured in the thymus.

Answer 1

Understanding the Question:
Lymphocytes are a type of white blood cell that carries out the body's specific immune response against pathogens.

Detailed Explanation:
There are two main classes of lymphocytes: B lymphocytes and T lymphocytes, both produced from stem cells in the bone marrow.
B lymphocytes mature in the bone marrow itself and, once activated, turn into plasma cells that secrete antibodies, giving humoral immunity that works mainly against pathogens circulating in blood and body fluids.
T lymphocytes migrate to the thymus to mature, and they directly attack infected or foreign cells, providing cell-mediated immunity, which is important against viruses hiding inside body cells and against cancer cells.
Together, B and T lymphocytes give the body its adaptive immunity, meaning the immune system can recognise a specific pathogen and remember it for a faster response next time.

Final Answer:
Lymphocytes are B cells and T cells that provide the body's specific, adaptive immunity, with B cells making antibodies and T cells directly attacking infected cells.