Key Terms — Stem Cells and Differentiation

📖 Key Terms — Stem Cells and Differentiation

Stem cell

An undifferentiated cell that can divide to produce more stem cells (self-renewal) and can differentiate into one or more specialised cell types.

Differentiation

The process by which a less specialised cell becomes a more specialised cell type, with a specific structure and function, by switching on certain genes and switching off others.

Embryonic stem cell

A pluripotent stem cell found in the inner cell mass of an early embryo (blastocyst), capable of differentiating into any type of cell in the human body.

Adult stem cell

A stem cell found in specific tissues of a developed organism (e.g., bone marrow). Usually multipotent — can only differentiate into the cell types of that particular tissue.

Meristem

A region of actively dividing cells found at the growing tips of roots and shoots in plants. These are the plant equivalent of stem cells and can differentiate into all plant cell types.

Therapeutic cloning

A technique in which the nucleus from a patient's cell is inserted into an enucleated egg cell to create an embryo genetically identical to the patient, from which embryonic stem cells can be harvested for medical treatment.

Specialisation

The process by which cells develop structures and features specifically suited to their function, as a result of differentiation.

Must memorise: A stem cell is an undifferentiated cell that can divide and differentiate into specialised cell types.

Must memorise: Differentiation is the process by which cells become specialised — same DNA, different genes switched on.

Must memorise: Embryonic stem cells are pluripotent (can become ANY body cell); adult stem cells are more limited.