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.
Platelets, or thrombocytes or yellow blood cells, are very small, irregularly shaped clear cell fragments (i.e. cells that do not have a nucleus containing DNA), 2â3 Âµm in diameter, which derive from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days.ed blood cells primarily carry oxygen and collect carbon dioxide through the use of haemoglobin, and have a lifetime of about 120 days. In the process of being formed they go through a unipotent stem cell stage. They have the job alongside the white blood cells of protecting the healthy cells.