V. Read the following extracts about stem cells. Answer the questions in the Discussion section
Stem cells are truly remarkable. They bridge the gulf between the fertilized egg that is our origin and the architecture that we become. They supply the cells that construct our adult bodies and, as we age, replenish worn out, damaged and diseased tissues. They renew themselves, resisting the powerful pull towards differentiation that overcomes more prosaic cells. And depending on the source, they have the potential to form one, many or all cell types of an organism.
Stem cell research has a history of more than 20 years, and has made some outstanding contributions to our understanding of haematopoiesis and mouse embryology. But the field has been transformed in the past few years by successes achieved in culturing human embryonic stem cells, the building blocks for every tissue we comprise, and in manipulating their differentiation in vitro. Below you can see three articles describing the achievements in the researches connected with the use of stem cells in treating a variety of human diseases and warning us against potential risks the method may involve.