What is the name of an unspecialised cell capable of differentiating into various cell types?

The correct answer is stem cell. Stem cells are unique in that they are unspecialised cells with the remarkable ability to develop into many different cell types. This includes the potential to become any type of cell needed for tissue repair and regeneration, such as muscle, nerve, or blood cells.

Stem cells exist in various forms, including embryonic stem cells, which can differentiate into all cell types, and adult stem cells, which typically develop into a limited range of cells related to the tissue in which they reside. This characteristic of flexibility in differentiation makes stem cells particularly important in developmental biology and regenerative medicine.

The other options refer to different types of cells that do not share this same capacity for versatility. Progenitor cells are more committed than stem cells; they are sometimes described as "committed progenitors," meaning they can only develop into a specific type of cell and are not truly unspecialised. Determined cells are already committed to a specific lineage and have lost the ability to differentiate into other types. Somatic cells are fully differentiated cells that make up most of the body tissues and organs, lacking the capacity to become other cell types.