Genes as the Fundamental Units of Hereditary Information <br />Genes represent the basic units of genetic information within the human body. They are ‎segments of DNA that carry the instructions for building proteins, which in turn regulate the ‎development of physical and biological traits.‎<br />‎1. How Do Genes Work?‎<br />• The human body contains approximately 20,000–25,000 genes distributed within the ‎nucleus of every cell.‎<br />• These genes function as an “instruction manual” that determines various traits such as ‎eye color, blood type, height, and even susceptibility to certain diseases.‎<br />• Example: If the gene responsible for eye color carries one version inherited from the ‎father (brown) and another from the mother (blue), the expressed color depends on the ‎dominant gene.‎<br />‎2. Observable Genetic Traits‎<br />There are evident traits determined directly by genes, such as:‎<br />• Skin color.‎<br />• Hair type (curly or straight).‎<br />• Height and body structure.‎<br />• Certain physical capabilities, such as metabolic rate or response to exercise.‎<br />Environmental Example: In some Gulf families, tall stature or shared facial features are ‎commonly observed due to inherited genetic influence.‎<br />‎3. Health-Related Traits<br />Genes do not only shape outward appearance; they play a vital role in health, including:‎<br />• Predisposition to diabetes or hypertension.‎<br />• The body’s response to certain medications.‎<br />• Immune system strength.‎<br />This explains why certain diseases are more prevalent within specific families, a phenomenon ‎known as genetic predisposition.‎<br />‎4. Interaction Between Genes and the Environment<br />It is important to recognize that genes are not the sole determinants of traits; they are ‎significantly influenced by environmental factors and lifestyle:‎<br />• For instance, a person may inherit genes predisposing them to weight gain, but exercise ‎and a healthy diet can help manage it.‎<br />• Similarly, intelligence is not solely determined by genes, but is shaped by education and ‎life experiences.‎<br />‎5. The Future of Genetics‎<br />The field of genetics and genetic engineering is advancing rapidly, opening wide horizons such ‎as:‎<br />• The ability to detect diseases before symptoms appear.‎<br />• Designing personalized medicines based on an individual’s genetic profile.‎<br />• Developing gene therapy techniques to correct inherited disorders.‎<br />________________________________________<br />Recent studies have shown that genes are carried on chromosomes within the cell nucleus, with ‎an estimated 20,000–25,000 genes in the human genome. They operate through a precise ‎mechanism known as gene expression, in which information is transcribed from DNA to RNA ‎and then translated into proteins responsible for biological structures and physiological ‎functions.‎<br />The Human Genome Project demonstrated that human traits are rarely determined by single ‎genes alone; rather, they arise from complex networks of multiple gene interactions (polygenic ‎traits) in addition to epigenetic modifications that regulate gene activity without altering the ‎DNA sequence.‎<br />Population genetics research further indicates that environmental factors (such as nutrition, ‎physical activity, and external conditions) interact with the genetic basis, explaining the ‎significant differences even among members of the same family. For example, the genetic ‎predisposition to type 2 diabetes may be either activated or suppressed depending on lifestyle.‎<br />Thus, human traits can be described as the outcome of a complex interplay between genes, ‎epigenetic modifications, and the environment. With the advancement of genomic sequencing ‎and gene therapy, genetics offers promising horizons in personalized medicine and disease ‎prevention.‎<br />https://www.un.org/sustainabledevelopment/ar/health/<br />Mustaqbal University <br />The First University in Iraq<br />