The word "cycle" in cell cycle refers to the regular pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells.
The cell cycle is the term that describes the development and growth of a cell, after its formation and until its reproduction (division into two daughter cells). In eukaryotic cells (cells that include a nucleus) the cell cycle is comprised of two major phases, the interphase and the mitosis. During interphase, the cell grows larger and duplicates its genetic material. During mitosis, the cell divides its genetic material and cytoplasm, creating two daughter cells.
The answer to your statement is True.
Answer:
Explanation:
Lymphocytes are the agranular cells of WBC. These are mainly 2 types - T lymphocyte and B- lymphocytes. Natural killer cells/ NK cells are also another type of lymphocyte. The lymphocytes are present in both blood and lymph. They play are responsible for both innate and adaptive immunity.
The natural killer cells are meant for both innate immunity and adaptive immunity. The T cells and B cells are responsible for adaptive immunity.
The humoral immunity is mediated by B cells while T cells are mediated the cell-mediated immunity. When an antigen enters into the body the B cells get to activate and it becomes effector B cells. These B cells are proliferated by mitosis and produce plasma cells. Plasma cells have antibodies which provide adaptive immunity.
Both the B lymphocytes and T lymphocytes are synthesized in the bone marrow. This process is called hematopoiesis. Then these 2 types of cells are separated and mature in different cells. Therefore, bone marrow is the precursor of B cells and T cells.
B lymphocytes are matured in bursa or MALT cells, while the T lymphocytes are matured in the thymus.
T cells are not the only form of lymphocytes found in lymphoid tissues. The lymphoid tissues are - bone marrow cells, WBC, thymus, spleen, lymph nodes. Macrophages are the larger WBC and one form of monocytes.
They are able to respond to the presence of invading organisms because they recognize the<u> antigen </u>on the surface of organisms. There are specific receptors on the surface of immune system cells.
