Totipotential cell

The term uncommitted cell is ambiguous. For opponents of the precommitment hypothesis it may mean a pluripotential or totipotential cell which may gain its antibody-synthesizing capacity as a consequence of contact with antigen. Proponents of the precommitment hypothesis accept that immature uncommitted cells do exist, but they postulate that uncommitted cells cannot be triggered by antigen. 

According to the accepted definition SC, resulting in only one type of the differentiated cells, are named unipotential (or monopotential), two - bipotential. Those cells which give the beginning to a few types of different specialized cells are named pluripotential or multipotential. Totipotential is the ability of cell to differentiate in all the types of cells and tissues of organism (in any of 350 specialized lines derivative of ectoderm, mesoderm and endoderm). 

The development of platelets or thrombocytes takes place chiefly in the bone marrow from primitive totipotential reticulum or stem cells. The normal concentration of thrombocytes in the peripheral circulation of the adult is approximately 250,000-355,000/mm . Thrombocyte activity is necessary in the process of coagulation. Quantitative platelet deficiency or thrombocytopenia is one of the most common causes of hemorrhagic diathesis, and it may be due either to decreased platelet production or to increased platelet destruction. 

What two properties define a stem cell Distinguish between a totipotential stem cell, a pluripotent stem cell, and a progenitor cell. 

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