DNA Has All The Needed Information To Create The Species From Which It Came From

Term Paper Title	DNA Has All The Needed Information To Create The Species From Which It Came From
# of Words	3113
# of Pages (250 words per page double spaced)	12.45

DNA

DNA has all the needed information to create the species from which it came from.  DNA consists of genes which are coded messages in the DNA.  These messages control the cell to be what it was intended to be for example a brain cell or a skin cell.  All cells in an organism have the same exact DNA sequence unless it has been mutated.  The reason why they all have the same DNA is because they all came from one cell, the embryo which replicated itself and these new daughter cells replicated themselves and so forth and so on.  Throughout this division they begin to differentiate meaning they become a specialized cell for a special purpose.  Weather it is a muscle cell which has developed special functions to contract or a white blood cell that has learned to engulf foreign bodies, they all still have the same DNA.  The only difference in these cells are the genes that are expressed.  Not all genes are expressed in a cell but only the necessary ones needed to perform its function.  Some cells don't become differentiated and are spread throughout the body.  These cells are called stem cells because they will continuously divide to produce cells that are needed in a specific location.  These cells are somewhat like a stem of a plant that will produce leaves where they can absorb light.
Throughout the division process, the DNA replicated itself before the cell divides.  During this time of replication, certain chemicals or just by chance can cause the DNA to have an error I the gene sequence, this is called a mutation.  The cell can be mutated so much that it can not replicate anymore and will just die, but some will not be mutated enough and will divide which can possibly lead to problems.  Cloning is not a well defines term, for example, scientist have been able to produce multiple offspring's with the same DNA since 1970. (******)  This procedure, which has even been done with humans, is called embryonic twinning.
Embryonic twinning begins with a fertilized egg.  The egg is agitated by a glass prove by rubbing the outer shell called the zona pellucida.  Within 24 hours, the fertilized egg will have gone through division and become four identical cells all surrounded by the same zona pellucida.  A short while later, these same cells will divide into a cluster of eight cells.  At this point, it would be safe to split these cells by using a glass scalpel to pry them apart.  This process disrupts the zona pellucida.  An artificial zona pellucida is made for each individual cell.  Once separated and with there own zona pellucida, they can be implanted into a female of that species and have them develop into twins, triplets etc.  All which are identical.(*****)
Another type of cloning which is extremely more complicated and is bringing up ethical questions is nuclear transfer.  Nuclear transfer is the development of an embryo from an adult cell.  Scientist believed that the differentiation of an adult cell was irreversible and once certain parts of the DNA were blocked, they could never be unblocked.  Scientist believed this because once a cell has developed and differentiated certain parts of the DNA which will not be used become twisted and tangles so tight that those genes could never again be expressed.  This theory was derived after an experiment done in the 1970's when cells transferred from adult amphibians developed into the tadpole stage but never into the adult stage. (Wilmut, et al. 810)  Since the tadpoles never developed to adults, the scientist believed the differentiation might even reprogram the cells DNA to an irreversible stage.
Nuclear tranfer is performed by removing the nucleus, which contains the DNA, of an oocyte, without disturbing the cytoplasm in the cell.  An adult cell is then made quescent, (Campbell 25) which never means the cell is starved from nutrients when it is at a certain phase of division.  This is done because the nucleus of the donor cell must be at the same phase as the cytoplasm of the enucleated cell.  The nucleus of the quescent cell is removed and transfered next to the enucl...

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