Using stem cells in medical therapiesSpec 3.17
In short
Stem cells can be grown into specialised cells to replace those damaged by disease or injury. Using embryonic stem cells raises ethical concerns because it involves destroying embryos. Society makes decisions by weighing scientific evidence about benefits and risks against ethical, religious and economic views, and by setting laws and regulations that control the research and its uses.
Stem cells could be used to treat conditions in which cells are lost or damaged, such as some forms of blindness, spinal injury, Parkinson's disease and type 1 diabetes. Cells would be grown in culture, directed to differentiate, and transplanted into the patient. Bone marrow transplants, which use adult stem cells from bone marrow, are already used to treat some blood disorders. Adult stem cells avoid destroying an embryo, but they can form only a limited range of cell types.
| For | Against |
|---|---|
| They could treat serious diseases and injuries that currently cannot be cured | Collecting embryonic stem cells destroys the embryo, which some people believe is a human life with the right to life |
| Spare embryos from IVF treatment would otherwise be destroyed | Some religious and moral views oppose any use of embryos; some people fear that it could lead to the creation of embryos for research |
| Stem cells divide indefinitely in culture, giving a large supply of cells | Risk of tumours if the cells divide uncontrollably after transplant, and of rejection or infection |
| Research gives scientific understanding of development and genetic disease | Treatments are expensive, and the benefits are still uncertain |
Scientists provide evidence about what is possible and the risks involved, but they cannot decide whether the research should be done. Society makes the decision. Governments set laws and set up regulatory bodies that license and monitor research (for example, strict limits on how long embryos may be kept). Ethics committees, religious and patient groups, the media and the public all contribute opinions. Decisions can differ between countries and change as the science develops.
In a 'discuss' answer, give arguments on both sides (benefits and objections), and say who decides: laws and regulation, based on scientific evidence and public opinion.
Written and checked against the Edexcel International AS Level Biology (XBI11) specification · Updated October 2026