1. Introduction to DNA<br />Deoxyribonucleic acid (DNA) is a molecule that encodes the genetic instructions used in the development, functioning, and reproduction of all known living organisms and many viruses. DNA is a long polymer made from repeating units called nucleotides, each of which consists of a sugar, a phosphate group, and a base. DNA is well-suited for biological information storage because the DNA backbone is resistant to cleavage, and the double helix structure provides the molecule with a built-in duplicate of the encoded information. The genetic information is often compacted by protease in the eukaryote and is stored in two membrane-bound packages in mitochondria and chloroplasts in plant cells. In eukaryotes, genetic information is replicated and passed on to the next generation by means of genetic recombination, oocytes, and spermatocytes.<br />All life depends on the DNA sequence of an organism. DNA represents the blueprint of an organism's genetic and other components and is passed on from one generation to the next via the process of reproduction. Genetic information is passed on from generation to generation through heredity. Many aspects of an organism's life and its personality are determined by its genetic structure. In the study of genetics, investigations are conducted at DNA's basic level. There are numerous benefits to understanding the DNA sequence in various fields, including disease management, blueprints for medical applications like gene therapy, and inbreeding avoidance in animal husbandry. By knowing the genetic sequence of an organism, some illnesses can be more effectively managed or treated.<br />2. The Structure and Function of DNA<br />Deoxyribonucleic acid (DNA) is a molecule that contains the biological specifications defining all forms of life. Structurally, DNA is made up of two strands coiled in a double helix configuration with active components specific to the formation of DNA. These two strands are comprised of individual nucleotide units that include a sugar, phosphate backbone, and a nitrogenous base. The base components that are involved include adenine, thymine, cytosine, and guanine. Adenine and thymine are composed of two hydrogen bonds that interact between the two nucleotide strands. Cytosine and guanine, however, are comprised of three hydrogen bonds. This specific hydrogen bond arrangement allows the double helix to possess complementary pairings.<br />The arrangement of these four nucleotide building blocks establishes the genetic blueprint of living systems in the human environment. Inserting information in DNA uses different orders of nucleotide sequences. A gene either lacks nucleotides coding for a protein or has a rich set. The human DNA genome consists of about 3 billion base pairs with 20,000–25,000 genes taken up by only 1.5% of the genome. The rest of the genome includes regulatory areas, introns, or other non-coding areas. DNA provides the means to regulate and carry out several of the cellular processes. Replication of DNA and transcription of DNA into ribonucleic acid (RNA), which is eventually translated into key enzymes or structural proteins, is fundamental for nuclear processes because all cellular activities and metabolic transformations are mediated by proteins. Proteins and their freedom to vary are direct outcomes of gene expression in terms of which proteins are produced in a particular cell. A gene is also the mechanism regulating how much protein occurs. Gene expression can be turned up and down for tissues in a number of manners.<br />3. Applications of DNA in Biology and Medicine<br />Recently, DNA has been used in diverse fields of biology and medicine. DNA can be used not only as material in research but also as a "tool" for application in biology, medicine, and genetic engineering. Cloning, genetic engineering, and gene transfer, which are based on the principle of genetic recombination and are among the applications of molecular cloning, have enabled humans to accumulate various valuable mutants in the field of basic medicine and have played a key role as a potential source of new drugs. In the field of genetic recombination, as the large-scale genome project is underway, a variety of modified genes or identified proteins can be moved together to create cells or organisms with new functions. Zinc-finger, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats are some of these interesting strategies. Tools that are able to modify genomes perform extremely high-resolution genome engineering using the human or microorganism genome sequence and have gained much popularity in various fields. Non-trivial gene transfer and gene modification by microorganisms are also used to perform genetically modified research and virus research related to base.<br />First, personalized medicine sequencing for individuals is essential for personalized medicine and is currently being considered for the birth assessment of individuals, targeted treatment of complex diseases, and broad precision medicine. Since the price of gene-sequencing technology has dropped, genetic recombination has brought precision medicine closer. Moreover, identifying the related protein also provides a molecular basis for understanding human disease, new drug research, preliminary toxicology, and basic risk assessment. In addition to the therapeutic and basic implications caused by genetic and epigenetic changes, they can also be used as clinically useful biomarkers or diagnostic targets. DNA/RNA-seq cancer adoptable sequencing in clinical practice shows high diagnostic accuracy and has the ability to dynamically monitor the condition. It can also be used to design targeted therapy by analyzing gene mutations and contribute to the good prognosis of patients. Moreover, the sequencing result is also applicable for the early detection of cancer and controlling the transfer of early precancerous individuals. In addition, it can be used for the detection and treatment of liver cancer, ovarian cancer, colorectal cancer, and a variety of tumors based on the numerous differential samples.<br />4. Ethical Considerations in DNA Research<br />Moral and ethical considerations surround the increasing role of DNA technologies in our lives. Research into genetics could uncover knowledge about our future health, could be used in ways that compromise individuals' rights and liberties, and could give rise to forms of eugenics and genetic discrimination, irrespective of whether any harm is really caused. Major ethical concerns include genetic privacy, consent for research, genetic nondiscrimination, and the equity of new genetic technologies. As this research holds the potential to inform the future of public health in our societies, it is important that people are well informed about the nature of the science so that an open and elucidative debate on the ethical implications can ensue. One of the major moral issues in genetic technologies involves 'playing god', 'tampering with the essence of humanity', and the eugenics dimension of genetic advancement. Expense and access are also key ethical issues as genetic technologies may have implications for the allocation of limited resources. Gene patenting is another area where the question of ownership in relation to DNA is being raised with some urgency, especially in the context of the human genome project and biobanking initiatives. In addition, genomic research on human populations must take account of the history of genetic research. As a relatively new field of investigation, it is critical that research is rigorously conducted and published, along with safeguarding mechanisms to protect both the privacy and consent of participants. Furthermore, the importance of policy guidelines that are relevant to genetic and other ethical concerns that arise from biobanking, and protecting cultural and social values, are areas that need to be constantly negotiated.<br />