What are stem cells ? Write their sources and any two uses.

Answer: Stem cells are unspecialised cells of the body that can divide repeatedly and can change into any type of specialised cell, such as nerve, muscle, blood or skin cells.

Sources: (1) embryonic stem cells from the inner cell mass of an early embryo (blastocyst); (2) adult stem cells from bone marrow, umbilical cord blood and adipose (fat) tissue.

Uses (any two):

1. To replace damaged or dead cells, e.g. in blood cancer (leukaemia) and thalassaemia through bone marrow transplantation.
2. To repair tissues damaged by injury, burns or diseases such as diabetes and heart attack (under research).
3. Umbilical cord blood can be preserved in a stem cell bank for future treatment of the child or family members.