A Level Biology Practice Exam

Totipotent stem cells possess the remarkable capability to develop into a complete organism from a single cell. This characteristic sets them apart from other types of stem cells, such as pluripotent and multipotent stem cells, which have more limited differentiation potential. Totipotent stem cells can give rise to all cell types in an organism, including both the embryonic and extra-embryonic tissues required for a functional organism. This includes the ability to develop into cells that make up structures such as the placenta and the embryo itself.

In contrast, the other options describe characteristics that do not apply to totipotent stem cells. For example, specifying that totipotent stem cells can only develop into skin or muscle cells limits their potential significantly. Additionally, mentioning that they can only differentiate into cells of the germ layer does not acknowledge their broader capabilities. The notion that they lose their potential after the first division inaccurately represents their ability to maintain totipotency for a limited number of initial divisions, particularly in early embryonic stages.