What best describes stem cells?

Stem cells are best described as undifferentiated cells capable of dividing. They have the unique ability to undergo numerous divisions while remaining in an unspecialized state, which enables them to later differentiate into various specialized cell types. This is fundamental to development, growth, and tissue repair in organisms.

The characteristics of stem cells allow them to perform essential functions in the body, such as replenishing differentiated cells in tissues that are regularly replaced, like blood and skin. Their potential for differentiation into a range of cell types highlights their importance in medical research and therapies, as they can be used for regenerative medicine to repair or replace damaged tissues and organs.

In contrast, specialized cells that cannot divide are not stem cells; they have a specific function and have lost the ability to proliferate. Dead cells without function describe cells that are no longer viable and do not contribute to any processes within the body. Lastly, cells with a fixed role in the body refer to differentiated cells that serve a specific purpose but do not possess the ability to transform into other types of cells, which distinguishes them from the versatile nature of stem cells.