8. All living organisms are composed of cells Unicellular organisms must carry out all of the functions of life in that one cell. Individual cells in multicellular organisms may not carry out all of the functions of life, but as a whole the organism will. This is because individual cells may become specialized to do a particular job. Cells become specialized through differentiation. Multicellular organisms also show properties that emerge from the interaction of their cellular components.

9. 7 Functions of Life

10. M R H G R E N

12. So why aren’t bacteria human size?

13. Cell Specialization Cells become specialized through… Differentiation But what does that mean?!?!

14. Stems cells are cells that retain the capacity to divide and differentiate along different pathways. It is necessary for embryonic development. It also makes stem cells suitable for therapeutic uses.

15. Embryonic Umbilical Cord Blood Adult – e.g. Bone Marrow New cells so no mutations Mutations may have accumulated Totipotent – can become any cell Limited potency “Easy” but controversial to obtain Umbilical cord discarded whether stem cells are used or not so not as controversial Difficult to extract but not controversial Removal of embryo cells kills the embryo Removal of cells does not kill the adult Likely to be genetically different from adult Perfect genetic match with adult source

16. Produce an essay on the therapeutic use of stem cells. You should talk about the sources of stem cells, their pros and cons and the arguments for and against stem cell research. You should also describe how they are used in the treatment of Stargardt’s disease and another disease of your choice. You should aim for around 800 words.