____________ stem cells can differentiate into embryonic & extraembryonic cell types. Such cells can construct a complete, viable organism. These cells are produced from the fusion of an egg & sperm cell. Cells produced by the first few divisions of the fertilized egg are also totipotent.
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In mammals, there are two broad types of stem cells: embryonic stem cells (ES cells) which are isolated from the inner cell mass of blastocysts and ________________ stem cells present in various tissues.
_____________ stem cells are the descendants of totipotent cells and can differentiate into nearly all cells, i.e. cells derived from any of the three germ layers.
In a developing embryo, stem cells can differentiate into all the specialized cells—ectoderm, endoderm and _____________.
Embryonic stem cells (ESCs) are _______________ and can give rise during development to all derivatives of the three primary germ layers: ectoderm, endoderm, & mesoderm. In other words, they can develop into each of the more than 200 cell types of the adult body.