DNA profiling, also known as DNA fingerprinting or genetic fingerprinting, is considered a valid means of identification because DNA is unique to each individual, except in the case of identical twins. The likelihood of two individuals having the same DNA profile is extremely low, making DNA profiling a reliable method of identifying individuals. This technique is commonly used in forensic science to help solve crimes by analyzing DNA samples from crime scenes and comparing them to the DNA profiles of suspects.
The structure of DNA (deoxyribonucleic acid) is a double helix, consisting of two strands of nucleotides that are held together by hydrogen bonds between their nitrogenous bases. The four types of nitrogenous bases found in DNA are adenine (A), guanine (G), cytosine (C), and thymine (T). The nitrogenous bases pair up in a specific way: A pairs with T and C pairs with G. This base pairing is known as complementary base pairing.
Genes are specific sections of DNA that encode for specific traits or characteristics. Chromosomes are structures that contain DNA and are located in the nucleus of cells. In humans, each cell contains 23 pairs of chromosomes, for a total of 46 chromosomes. One chromosome in each pair is inherited from the mother, and the other is inherited from the father. Each chromosome contains many genes, and the specific combination of genes on each chromosome determines an individual's traits and characteristics.
Therefore, DNA is the genetic material that carries the information necessary for the development and functioning of all living organisms, and genes and chromosomes are the structures within DNA that determine the traits and characteristics of an individual. DNA profiling can identify individuals by comparing the unique patterns in their DNA, which are determined by the specific combination of genes on their chromosomes
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