PDF | On Mar 31, , Lakna Panawala published Difference Between Adult and Embryonic Stem Cells | Find, read and cite all the research. These include embryonic stem cells that exist only at the earliest stages of development and various types of tissue-specific (or adult) stem cells that appear. Unlike embryonic stem cells, the use of adult stem cells in research and therapy is not controversial because the production of adult stem cells does not require. Embryonic Stem Cells The first cells to form after a sperm fertilizes an egg. · Adult Stem Cells Mature stem cells that replenish blood, skin, gut and some other cells.