Colin Pitchfork was then sentenced to life in prison. Polymerase chain replication is a biochemical technology in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence. The first time that PCR was used was in a forensic case dealing with evidence of locus. Throughout history technology has helped to produce more ways of using DNA as a forensic tool.
In this essay we will discuss about: Definition of DNA Replication 2. Mechanism of DNA Replication 3. Each half then serves as a template for nucleotides available in the cells which are joined together by DNA polymerase.
The nucleotides are guanine, cytosine, adenine and thymine. This process is important in all known forms of life and the general mechanisms of DNA replication are the same in prokaryotic and eukaryotic organisms. In other words, it is the process of duplicating the DNA to make two identical copies.
The main points related to DNA replication are briefly presented below. The process of DNA replication takes place during cell division.
The DNA replication takes place during S sub stage of interphase. In prokaryotes, DNA replication is initiated before the end of the cell cycle.
Eukaryotic cells can only initiate DNA replication at the beginning of S phase. In humans and other eukaryotes, replication occurs in the cell nucleus, whereas in prokaryotes it occurs in the cytoplasm.
Prokaryotes have only one active replication site, but eukaryotes have many. It is possible that during replication on strand of DNA can replicate continuously and the other discontinuously or in piece.
The continuously replicating strand is known as leading strand and the discontinuously replicating strand is known as lagging strand. When one strand of DNA replicates continuously and other discontinuously, it is called semi-discontinuous replication.
Earlier it was thought that DNA replicates discontinuously. But now it is believed that DNA replication is semi-discontinuous. Short segments of nucleotides are synthesized in the lagging strand of DNA as a result of discontinuous replication.
These are called Okazaki after the name of discoverer. Okazaki fragments are about 1, bases in length in prokaryotes, and bases in eukaryotes 4. In other words, the process is catalized by the polymerase enzyme.
In eukaryotes, four types of polymerase enzymes, viz. The alpha is associated with initiation, and delta extends the nascent strands. DNA polymerase epsilon and beta are used for repair.
DNA poly II is exclusively involved in repair. Currently, six families of polymerases A, B, C. D, X, Y have been discovered.
The synthesis of one new strand takes place in and that of other in opposite direction. The replication may take place either in one direction or in both the directions from the point of origin.
When replication proceeds in one direction only, it is called unidirectional replication. When the replication proceeds in both the directions, it is called bidirectional replication.Can DNA Witness Race?: Forensic Uses of an Imperfect Ancestry Testing Technology (Article begins on next page) The Harvard community .
Key Study Variables Table 4. National & Study Criminal Justice Outcome Data Table 5. Descriptive Characteristics of Assault Incidents Table 6.
Summary of Forensic Evidence for Assault Cases 46 with DNA evidence were much more likely to reach court and had a positive effect on juries’. Essay # 1. Meaning of DNA: A nucleic acid that carries the genetic information in the cell and is capable of self-replication and RNA synthesis is referred to as DNA.
The Admission of DNA Evidence in State and Federal Courts George Bundy Smith THE ADMISSION OF DNA EVIDENCE IN STATE AND FEDERAL COURTS U.S. Congress Office of Technology Assessment, Genetic Witness: Forensic Uses of DNA Tests, at , ; Prescott et al., supra note 1, at Harlan Levy, And the Blood Cried Out: A.
ADVERTISEMENTS: In this essay we will discuss about: 1. Definition of DNA Replication 2. Mechanism of DNA Replication 3. Evidences for Semi-Conservative DNA Replication 4. Models for Replication of Prokaryotic DNA. Essay # Definition of DNA Replication: DNA replicates by “unzipping” along the two strands, breaking the hydrogen bonds which .
DNA is a tool of great use throughout the world. Especially when it comes to the field of forensic science, DNA is the most important tool of all.