DNA

DNA is a thin, chainlike molecule found on every living cell on earth. It directs the formation, growth, and reproduction of cells and organisms. DNA is found in mainly within a cell’s nucleus, in structures called chromosomes. DNA consists of thousands of smaller chemical units (nucleotides). There are four DNA bases: Adenine, Guanine, Thymine, and Cytosine. “The exact amount of each nucleotide and the order in which they’re arranged are unique for every kind of living thing and that’s what makes us so different” ( Relly, 98, 2000 ). DNA without a doubt is probably one of the greatest wonders most important to the existence of life. DNA has not only helped us understand more about us but it has helped us in other ways such as DNA fingerprinting. DNA fingerprinting is a method of identification that compares fragments of deoxyribonucleic acid. “DNA has helped science advance in multiple ways and society as well” ( Carroll, 659, 1997 ). A DNA fingerprint is constructed by first extracting DNA sample from the body tissue or fluid such as hair, blood, or saliva. The sample is then segmented using enzymes, and the segments are arranged by size using a process called electrophoresis. The segments are marked with probes and exposed on X-ray film, where they form a pattern of black bars. If the DNA fingerprints produced from two different samples match, the two samples probably came from the same person. DNA fingerprinting was first developed as an identification technique in 1985. Thanks to that we can figure out if a certain woman is the biological mom of that child. It has also helped in criminal and civil investigations. Through the DNA analysis of genetic materials investigators can identify individuals in criminal and other cases. Theses cells can be obtained from almost any body fluid or tissue, including bone, blood semen, hair, or teeth.