Embryonic Stem Cells are present in all developing embryos, they are the building blocks of all 260 different types of cells in the human body. Whilst there may be only a small number of these stem cells in the embryos they are able to divide into millions of cells that build the miracle of the human body. Human Embryonic Stem Cells (hESCs) are only completely totipotent during the 5-6 days of the fertilised egg, after this period the stem cells are limited and become pluripotent which appear when the blastocyst forms. Despite the limitation of these pluripotent stem cells compared to the totipotent stem cells, they can still differentiate into most of the cells in the body for example specialised cells like, nerve, heart, liver and so on, one exclusion which these cells can not differentiate into are placenta cells which are essential for the development of the foetus.
The pluripotent cells are present in a developing foetus and are responsible for the creation and development of organ tissues such as heart, liver, lung tissues etc, they can also be used to repair damaged tissues. These stem cells are able to be extracted from the inner cell mass of a blastocyst and can be used in any area of the body as they can differentiate and replace damaged tissues or non-functioning tissues. For this reason the use of embryonic stem cells can be used to transform medicine around the world if it was to work successfully or may lead to a dead end, this will be the focus of my essay.
The first major breakthrough of stem-cell testing began with the cloning of "Dolly" the sheep (1996), the effort to create a genetically mammal was only the start, since then many governments have realised the potential benefits that stem cells hold and as a result have lifted restrictions and allowed testing on embryonic stem cells. Also there has been very extensive research programmes, which all have developed the field even further. Some have given us a glimpse of the potential of...