PTE Reading MC Single Answer: Stem cells are cells that can self-renew and differentiate into specialized cell types.…

Stem cells are cells that can self-renew and differentiate into specialized cell types. Because of their potential to replace diseased or defective human tissue, stem cells are seen by scientists as key to developing new therapies for a wide range of conditions, including degenerative illnesses and genetic diseases. Treatments based on adult stem cells – from sources such as umbilical cord blood – have been successfully developed, but what makes stem cell research controversial is the use of embryonic stem cells. Not only do embryonic stem cells reproduce more quickly than adult stem cells, but they also have wider differentiation potential. The main opponents to stem cell research are pro-life supporters, who believe that human life should not be destroyed for science. Advocates of stem cell research counter this crucial point by saying that an embryo cannot be viewed as human life and that medical advances justify the destruction of embryos. Furthermore, stem cell research utilizes the thousands of surplus embryos created for in vitro fertilization treatment.