What term refers to the measure of the ability of a cell to form more specialized cells?

The term that refers to the measure of the ability of a cell to form more specialized cells is potency. Potency describes the potential of a stem cell to differentiate into various types of cells. It is a broad concept that encompasses different levels of specialization. For instance, totipotent cells can develop into any cell type in the organism, while multipotent cells are limited to developing into a few closely related cell types. Therefore, potency is a key property that defines how versatile a stem cell is in terms of development and specialization.

While pluripotency is a specific form of potency referring to the ability of a stem cell to differentiate into almost all types of cells in the body (excluding extra-embryonic tissues), it is not as general a term as potency. Differentiation factor and plasticity are also related but do not capture the broad measure of a cell's potential to develop into specialized cells as effectively as potency does. Differentiation factors are specific signals that promote differentiation, and plasticity refers to the ability of cells to change their function or phenotype, which is not the primary focus of this question.