The Treaty of Kanagawa was an 1854 agreement between the United States of America and the government of Japan. The treaty, which was essentially imposed on the Japanese by threat of force, opened two Japanese ports for trade with American ships. The treaty was the first modern treaty Japan had with a western nation.
Platelets have no cell nucleus: they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow, and then enter the circulation. These unactivated platelets are biconvex discoid (lens-shaped) structures, 2â3 Âµm in greatest diameter.
Megakaryocytes are huge cells that break into fragments to form platelets. These cell fragments have no nucleus, but do contain structures called granules. The granules house proteins that are necessary for clotting blood and sealing breaks in blood vessels.A single megakaryocyte can produce anywhere from 1000 to 3000 platelets. Platelets circulate in the blood stream for about 9 to 10 days.latelets, also called thrombocytes, are the smallest cell type in the blood. Other major blood components include plasma, white blood cells, and red blood cells.