3.18

Question 1

how do stem cells become specialised through differential gene expresion?

Answer 1

1) Stem cells all contain the same genes, but not all of them are expressed because not all of them are active.
2) under the right conditions, some genes are activated and other genes are inactivated.
3) mRNA is only transcribed from the active genes.
4) the mRNA from the active genesis then translated into proteins.
5) these proteins modify the cell-they determine the cell structure and control cell process.
6) Changes to the cell produced by these proteins cause the cell to become specialised (differentiated). These changes are difficult to reverse, so once a cell has differentiated it stays specialised.