What is the difference between a skin cell and a stem cell?

A) A skin cell gives rise only to other skin cells and a stem cell gives rise only to stem cells.
B) A skin cell has a full complement of DNA, but a stem cell does not.
C) Stem cells have telomerase; skin cells lack telomerase.
D) Stem cells are not found in humans, while skin cells are.
E) Stem cells arise from skin cells when select genes are turned on.

Stem cells have telomerase, an enzyme that protects the ends of chromosomes from shortening during cell division. Skin cells do not have telomerase and therefore have a limited number of times they can divide before they stop reproducing. Stem cells have the ability to differentiate into different types of cells, whereas skin cells are specialized and only give rise to other skin cells. The other choices are incorrect: A is not true as stem cells can differentiate into various cell types, B is incorrect as both skin cells and stem cells have a full complement of DNA, D is incorrect as stem cells are found in humans in various tissues and organs, and E is incorrect as stem cells are not derived from skin cells, but rather develop separately during embryonic development.