PATHOLOGY

Detailed explanation-1: -The zygote or fertilized egg is, of course, a totipotent stem cell. The known and well characterized totipotent stem cells are found only in early embryonic tissues and derive usually from the first few cell divisions after fertilization.

Detailed explanation-2: -Embryos produced by either fertilization or by cloning begin as a single-cell zygote that is (by definition) totipotent.

Detailed explanation-3: -Consistent with the definition, the zygote is totipotent, meaning that this single cell has the potential to develop into an embryo with all the specialized cells that make up a living being, as well as into the placental support structure necessary for fetal development.

Detailed explanation-4: -What are stem cells? Embryonic stem cells are special cells found in very early stage embryos (fertilized eggs). They are undifferentiated cells. This means that they have not yet developed into a cell that performs a specialized function (such as skin, heart, or nerve cells).