Branches of Genetics:
Science of Genetics has occupied a key position among modern sciences. Its field of study extends from molecular to population levels. It exhibits either or indirect relationship with many branches of science.
1. Cytogenetics: The heredity units or genes are formed from DNA. These are an integral part of chromosomes. The chromosomes are contained in the nucleus. The nuclei of germ cells are the only bridge between successive generations. Therefore, our knowledge of the structure of the nucleus, and nuclear components. Finally, the structure and properties of nucleic acids have helped in understanding the physical and physiochemical aspects of heredity. The two sciences (Cytology and Genetics) are so closely associated that they jointly constitute ‘Cytogenetics‘.
2. Biochemical Genetics: The chemistry of chromosomes, genes, and nucleic acids and the chemistry of various processes related biochemical study of genetic material is named ‘Biochemical Genetics‘.
3. Physiological Genetics: Genetics helps in explaining some very important physiological characteristics like blood groups. Rh factor, alkaptonuria, sex-differentiation, sex-determination, etc. Some physiological abnormalities like sickle cell anemia, etc. It can be explained with the aid of genetic knowledge. Physiology also assists in explaining the expression of genes or genetic factors.
4. Clinical Genetics: Genetics has also helped in finding out the root cause of certain diseases like hemophilia, diabetes, color, blindness, erythroblastosis foxtails, and many others. All these diseases are caused on account of defective genotypes. Moreover, serology and blood transfusion are the two most important fields, where genetics has directly assisted physiology and helped in saving the life of innumerable persons.
5. Radiation Genetics: The study of the effect of radiation on genes and the change in their expression is being studied widely and forms, the basis of radiation genetics.
6. Microbial Genetics: Bacteriology has proved a boon for the study of a number of genetic problems. Major studies on the genetic material (genes and chromosomes) have been conducted on bacteria and viruses. This has unfolded several doubts. The most important concept that genes are DNA has been evidenced from the studies conducted on viruses, bacteriophages, and bacteria.
7. Behavioural Genetics: Several mental characteristics like idiocy, intelligence, talent, etc are heritable. The study of these characters has been named Behavioural Genetics. It naturally establishes a link between Genetics and Psychology.
8. Plant Genetics: Knowledge and techniques of genetics are employed for the improvement of plants yielding cereals. By cross-breeding, geneticists have tried to obtain such strains of crop plants that have better yields or are more resistant to diseases, or have more nourishing value.
9. Animal Genetics: Artificial insemination has been tried in animals to obtain genetically superior strains of game animals (like horses, pigeons, etc.) or milk-producing animals (like cows, buffalo, etc.)
10. Bimetric Genetics: Statistics has furnished important and indispensable tools to genetic researchers.
11. Human Genetics: The study of bacterial and viral genetics has helped P.H.E (Public Health and Engineering Dept.) to unlock several problems of human health and hygiene. It has therefore helped in improving the ecological environment of human beings.
12. Development Genetics: The most important phenomenon of embryology, the development of a complicated body organization from a single cell – ‘zygote’ with the differentiation of various organs, structures,s, and characters in a definite direction must be controlled in all essentials by the genotype of the zygote. Therefore, the science of genetics and embryology are closely linked. As a matter of fact, biochemical, physiological, and embryological genetics can not be isolated from one another.