Final answer:
Adult stem cells are better for stem cell therapy due to lower immune system rejection risk, absence of ethical concerns, and ease of obtaining them from the patient's own body compared to embryonic stem cells.
Step-by-step explanation:
Embryonic stem cells present concerns due to potential immune system rejection and ethical issues arising from the use of embryos. Adult stem cells, however, pose a lower rejection risk since they can be harvested from the patient's tissues, circumventing immune response and ethical dilemmas concerning embryo use. Although they have a limited differentiation potential compared to embryonic stem cells, technologies like induced pluripotent stem cells (iPSCs) are advancing to enhance their versatility.
Furthermore, banking sources of stem cells such as cord blood or deciduous teeth provides a personalized source of stem cells, further reducing the risk of immune rejection. iPSCs generated from adult cells offer a promising alternative to embryonic stem cells, carrying the capacity to generate cells characteristic of all three germ layers without the associated legal, ethical, or immunological issues.