Stem cells

Question 1

Describe 2 ethical concerns regarding the use of ESCs that are no longer relevant with the development of iPSCs [2]

Answer 1

1. No destruction of embryos (which are viable living organisms; ESC > develop into embryo > develop into a potential human)
2. No extraction of stem cells from embryo to make replacement body cells (source of spare parts)

Question 2

Explain 2 advantages of using iPSCs > ESCs in gene therapy [4]

Answer 2

1. Obtained directly from the recipient
   » genetically identical (no foreign antigens)
   » no risk of rejection by immune system
   » no need to ensure immunocompatibility
   » no need for immunosuppressants (weaken immune system)
2. No destruction of embryos
   » avoid moral issues
3. Easier to obtain iPSCs in greater numbers
   » can be obtained from any differentiated somatic cell
   » vs. ESCs from ICM of blastocyst

Question 3

Explain the advantages of ESCs > iPSCs

Answer 3

1. Lower risk of uncontrolled CD

vs. artificially reprogrammed by insertion
vs. from adult somatic cells - late in developmental stages&raquo_space; may have accumulated mutations

2. No need to reprogram cells
   vs. low reprogramming efficiency