DNA is formed when these monomer nucleotides join together to from a polymer. DNA consists of a double strand, which twists, resembling a twisted ladder where the base pairs form the rungs. This DNA sequence is very important as it specifies the traits of a particular human beings. DNA carries the genetic information that codes for amino acids thus coding for proteins which have vital roles in the human body for example they make antibodies, enzymes and are blood carrier molecules.
DNA replication is semi conservative, ‘Meselson and Stahl tested the theory that DNA replication was semi conservative’4. They used heavy Nitrogen, which was radioactive and light Nitrogen (normal nitrogen). They found that the DNA made contain one strand from the original DNA and the other was new. During semi- conservative replication the original strand unwinds and the hydrogen bonds, which hold the two strands together, are broken. Free nucleotides move along the exposed strands and they pair with the complementary bases. DNA polymerase enzyme is used to speed this process up.
Many countries are involved in the human genome project where they are all trying to find the sequencing for particular parts of the human genome. The project was started in 1990 and is near completion. These countries are working together researching different parts of the genome. There results from their research is all brought together and in this way they will be able to sequence the whole human genome more quickly
The human genome project has been supported by the British government where it was ‘allocated 11 million pounds over a three year period to set up the project’2 it was allocated a further ‘4.5 million in 1992’2. Although this may seem a lot of money but many scientists believe that in the long run it will benefit the British economy in that less money will be spent on the dispensing of medication and treatment on the NHS for people who suffer genetic disorders. Therefore reliving the NHS of pressure and saving
Rehana Begum
money which can be used elsewhere. If the whole human genome is sequenced and known, it is then possible to rectify the genetic disorder a person is suffering from. For example if someone suffers from the disease Cystic Fibrosis, they can undergo gene therapy where gene with the default can be removed and replace with the normal gene. As the genome will be known therefore the appropriate gene can be synthesised in the laboratory.
Many people disagree with the vast amounts of money being spent on the genome project, as they believe that there are many ethical and moral issues that are ignored. As people believe that having ‘greater genetic knowledge maybe used to discriminate unjustly between individuals’5. If a genetic disorder for example is found in an unborn child then it can be killed due to this knowledge that we have of the genetic coding. Whilst others believe that people in the developing world will not be able to used the information found from the genome project.
