Crjs478 Db3nameclassdateprofessordnadna Or Deoxyribonucleic Acid Is Th ✓ Solved

CRJS478-DB3 Name Class Date Professor DNA DNA or deoxyribonucleic acid is the unique genetic code found in the genetic material of humans and animals. Upon the discovery of this unique genetic code, DNA began an incredibly useful tool for law enforcement. George Mendel was the first scientist to perform experiments based on human genetics. The discovery of DNA began with Fredrick Griffith who conducted experiments and pointed out DNA was the molecule of inheritance. Oswald Avery was next in advancing DNA when he was able to definitively prove the inheritance molecule followed by Watson and Cricks model of DNA, the double helix.

DNA is made up of a complex set of molecules that make up a unique code that can be identified to one person. DNA is made up of nucleotides. A nucleotide is made up of three parts: a phosphate group, a 5 carbon sugar (deoxyribose in DNA), and a nitrogenous base (Doublie, 1998). Nucleotides arrange themselves in unique patterns that make-up the DNA code. DNA is arranged in a ladder like structure known as the double helix.

The process by which DNA replicates is called cell replication. When cells split however not every cell will create new DNA. Before new cells can be created the DNA in a cell must replicate itself in order for the cell to divide (Ophardt, 2003). This process will be dependent whether or not the cell splitting is a prokaryote or a eukaryote. Each cell that splits will contains a new and an old strand of DNA.

These strands of DNA wind together with proteins holding it together in order to form the double helix. The relationship between DNA, genes, and chromosomes involves the relationship to heredity. Through this relationship the DNA pattern that is unique to every individual with the exception of identical twins. Every DNA strand has the genetic material passed on by former generations and are made of little chromosomes. DNA analysis allows forensic scientists to develop a DNA profile that can be used to be match to a criminal suspect or even the unidentified.

References Doublie S., Tabor S., Long A., Richardson C., and Ellenberger T. (1998). Crystal Structure of a Bacteriophage T7 DNA Replication complex at 2.2 A Resolution. Nature 391: . Ophardt, C. (2003). DNA Replication. Retrieved November 26, 2013 from Geol 1 001.jpg Geol 4 001.jpg Geol 2 001.jpg

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Understanding DNA and Its Role in Forensic Science
DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all living organisms. It serves as the blueprint for the biological processes essential for life and is fundamental to the field of forensic science. The journey of unveiling DNA's significance can be traced back to early genetic experiments by scientists like Gregor Mendel and furthered by pivotal discoveries from scientists such as Frederick Griffith, Oswald Avery, James Watson, and Francis Crick (Friedman, 2013). This paper explores the structure of DNA, its replication process, its relation to heredity, and how it serves law enforcement in criminal investigations.
The Structure of DNA
DNA is composed of two long strands forming a double helix, which resemble a twisted ladder (Watson & Crick, 1953). Each strand is made up of nucleotides, which consist of a phosphate group, a sugar molecule (deoxyribose for DNA), and four nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G). The sequence of these bases encodes genetic information. Importantly, the pairing rules—A with T and C with G—are crucial for the correct replication and transcription of genetic information (Lodish et al., 2000).
Forensic analysis often focuses on specific areas of the DNA that are highly variable among individuals; these areas of variation are known as Short Tandem Repeats (STRs) (Butler, 2005). STR analysis provides a DNA profile that can be matched with biological evidence collected from crime scenes.
DNA Replication
DNA replication is a fundamental biological process that ensures genetic material is passed accurately from one generation to the next (Ophardt, 2003). Prior to cell division, the DNA must replicate itself, producing two identical copies. This process involves several key steps:
1. Initiation: The double helix unwinds, and enzymes like helicase break the hydrogen bonds between base pairs, separating the strands.
2. Elongation: DNA polymerase enzymes synthesize new strands by adding complementary nucleotides to each original strand (Kornberg, 2000).
3. Termination: Once replication is complete, the DNA molecules rewind into their double helical structure. Each daughter cell inherits one original and one new strand of DNA (Ophardt, 2003).
This mechanism ensures fidelity during DNA replication, although occasional errors or mutations may occur. Such mutations can contribute to genetic diversity but can also have implications for areas such as forensic analysis.
Heredity and Chromosomes
DNA's importance in heredity cannot be overstated. Each cell in a human body contains chromosomes, which are tightly packed structures of DNA that carry genes—units of heredity that determine individual characteristics (Griffiths et al., 2000). Humans typically have 23 pairs of chromosomes, half inherited from each parent. This unique combination generates the genetic identity of an individual, except in the case of identical twins who share nearly identical DNA.
Gene expression involves the transcriptions of genes into messenger RNA (mRNA) and subsequent translation into proteins (Berg et al., 2002). These proteins play vital roles in various biological functions, and any changes in the DNA sequence can affect protein synthesis, potentially leading to hereditary diseases.
Forensic Application of DNA
The application of DNA in forensic science has revolutionized law enforcement and criminal justice. DNA profiling allows forensic scientists to match biological evidence found at crime scenes—such as blood, hair, or bodily fluids—to potential suspects (Butler, 2005). With databases such as the Combined DNA Index System (CODIS), law enforcement agencies can compare DNA profiles against known offenders and unsolved cases, increasing the chances of identifying the perpetrator (Nijman et al., 2009).
Furthermore, DNA evidence not only assists in criminal investigations but can also exonerate individuals wrongfully convicted of crimes. Advances in DNA technology have made it possible to re-examine old cases and provide closure to victims and their families (Cole, 2009).
Ethical Considerations
While DNA profiling is a powerful tool in forensic science, it raises several ethical and privacy concerns. The collection and storage of DNA profiles must be managed carefully to prevent misuse or discrimination (Lynch et al., 2008). Striking a balance between public safety and individual privacy rights is an ongoing dialogue in the field of forensic science.
Conclusion
In summary, DNA is not only a crucial component of biological identity but also serves as a vital tool in forensic science for criminal investigations. The unique structure of DNA, its replication process, and its relationship to heredity all underscore its significance in understanding human genetics. As technology advances, so will the applications of DNA in forensic science, highlighting the need for ethical considerations as society navigates these powerful scientific capabilities.
References
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2. Butler, J. M. (2005). Forensic DNA Typing: Biology and Technology Behind STR Markers. London: Elsevier Academic Press.
3. Cole, S. A. (2009). 'Pearl's Perfect DNA Profile: The Ethics of Forensic DNA in the Post-9/11 Era'. Theoretical Criminology, 13(1), 23-47.
4. Doublie, S., et al. (1998). Crystal Structure of a Bacteriophage T7 DNA Replication complex at 2.2 A Resolution. Nature, 391.
5. Friedman, L. M. (2013). The Importance of Watson and Crick’s Discovery of DNA's Structure. Nature Reviews Molecular Cell Biology, 14(8), 499.
6. Griffiths, A. J. F., et al. (2000). An Introduction to Genetic Analysis. New York: W.H. Freeman.
7. Kornberg, A. (2000). DNA Replication. Science, 288(5470), 1387-1393.
8. Lynch, M., et al. (2008). 'The New Forensics: The Challenge of DNA Profiling'. New Genetics and Society, 27(3), 217-231.
9. Nijman, J., et al. (2009). The Role of DNA Profiling in Law Enforcement. European Journal of Criminal Policy and Research, 15(3), 245-260.
10. Ophardt, C. (2003). DNA Replication. Retrieved from http://www.mhhe.com/biosci/genbio/virtual_labs/flash/dna_replication.html
11. Watson, J. D. & Crick, F. H. (1953). Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid. Nature, 171(4356), 737-738.