Ethical Issues Because adult stem cells can be obtained directly from the body of a willing donor, research with these cells has raised few ethical questions to date. This is not the case with embryonic stem cells, which are generally obtained from very early embryos.

Most techniques for harvesting embryonic stem cells cause the destruction of an embryo. For this reason, individuals who regard the embryo as entitled to the rights and protections of any human being object to such work. This concern has made government funding of embryonic stem cell research an important political issue. Groups seeking to protect embryos oppose such research as unethical. Other groups support such research as essential for saving human lives and argue that it would be unethical to restrict research. Human embryonic stem cell research is controversial because the arguments for it and against it both involve ethical issues of life and death.

It is possible, however, that in the not-too-distant future, both ethical concerns will be addressed with a technological solution. Some recent experiments have suggested that there may be ways to extract a small number of stem cells from an early embryo without damaging the embryo itself. Other experiments have shown that it is possible to switch “on” a small number of genes that reprogram adult cells to look and function like pluripotent embryonic stem cells. Such a technique would do away with the need to involve embryos at all. It also might make it possible to tailor specific therapies to the needs of each individual patient. Approaches like these, if successful, might allow potentially lifesaving research to go forward while avoiding any destruction of embryonic life.

In Your Notebook Make a two-column chart that lists the benefits and issues related to stem cell research.

10.4 Assessment

Review Key Concepts

1. 1. Review What happens during differentiation?

   2. Apply Concepts What does “mapping” refer to in the process of cell differentiation?

2. 1. Review What are stem cells?

   2. Compare and Contrast How are embryonic stem cells and adult stem cells alike? How are they different?

3. 1. Review Summarize the potential benefits and issues of stem cell research.

   2. Form an Opinion How might technological advances help address the ethical concerns surrounding stem cell research?

Apply the Big idea

Cellular Basis of Life

4. Use what you learned in this lesson to discuss how cells become specialized for different functions. Include an explanation of how the potential for specialization varies with cell type and how it varies over the life span of an organism.

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