Genetics is a special area of Biology which focuses on heredity (inheritance). For common people, it is looked at the exercise of matching people’s look, character etc. and frequent comment comes as “the person is like father, like mother etc. It is also commonly believed that all these similarities in character, look are related to blood, which is absolutely wrong.
Heredity is actually related to transmission (passing) of genes from one to next generation. Johann Gregor Mendel, a priest cum scientist, through his work on pea plants, discovered the fundamental laws of heredity and he is considered the father of modern genetics. Mendel was an interesting personality who being by profession as priest, though pursued scientific research and set the trend of a new discipline whose vastness, depth and applications are nowadays beyond imagination.
He proved that some factors (units of inheritance) in pairs are inherited as distinct units, one from each parent (Father and Mother). Mendel traced back the segregation of parental genes and their appearance in the offspring as dominant or recessive traits (character). He also established that this genetic transmission is not random, but follows a mathematical patterns of inheritance from one generation to the next (1). The factor (units of inheritance) described by Mendel, through subsequent researches, has been proved to be genes which all animals inherit from their parent.
Every life on earth is unique and this uniqueness is brought by genes. Human has approximately 25,000 genes. These 25, 000 Genes control your appearance (structure) and functions (what you do at every moment) (2). Life is made of cells (primary unit) and as an example one human body in average contains approximately (35 – 40) trillion cells depending upon the body size. And all these cells at their center (called nucleus for higher form of life and nucleoid for lower form of life) stored a chemical called DNA (Deoxy ribonucleic acid) and genes are made of this chemical DNA. Genes are arranged inside the nucleus with a structure called chromosomes. Humans have 23 pairs of chromosomes and genes are located in the chromosome in pairs (two copies).
The composition of each genes is usually changes over the times which is termed in genetics as mutation, it means introduction of a change (s) in the gene. Even new genes are evolved (being created) by several genetic processes (e.g., Duplication, Fusion and Fission, Lateral gene transfer etc.). Scientist have also developed the method of isolating and modifying the genes in the laboratory (called as Genetic Engineering), and make use of the derived engineered genes to develop industrial, agricultural, medical, and other technological applications (emerged as a discipline called Biotechnology).
Apart from the tremendous diversification of the discipline Genetics, currently the knowledge of human and clinical genetics have generated renewed interest mainly because knowledge of variation of human genes is helping to study the role of genes in the development of human diseases and their better management procedures. Quite a few human diseases are manifested due to critical mutation incurred in the genes. Choice of life style choices and quality of living environment has tremendous implications in bringing new mutation in the genes. Mutations responsible for the disease is usually inherited form earlier generations and therefore it is essential to trace the disease history of the family. Though it is not possible to revert the mutation in causing the disease at this stage of research and application, but changes in life.
Style and living environment can help to attenuate the effect of the disease. Some of the common diseases (multi-factorial inheritance) due to inheritance are diabetes, cancer, heart disease, high blood pressure, Alzheimer's disease, arthritis, and obesity etc. However, there is huge potential from undergoing current studies in near future in the development of genetic technology in directly reversing the mutation and hence complete cure. Voila.
3) Kessler C. (2018) Genomics and Precision Medicine: Implications for Critical Care. AACN Adv Crit Care. 29(1):28-35.
Dr. Susanta Pahari is a Professor of Biochemistry in Skyline University Nigeria. He has a PhD. in Biochemistry from University of Calcutta, India.