The following points highlight the top four applications of genetics. The applications are: 1. Taxonomy 2. Agriculture 3. Medicine 4. Evolution.
Application # 1. Taxonomy:
Genetic characters like chromosome number and karyotypes are of taxonomic significance. Chromosome number helps in classification of plants. For example, the genus Triticum to which wheat belongs has been classified into three groups, viz., diploid, tetrapod and hexaploid.
Similarly, the genus Gossypium to which cotton belongs has been classified on the basis of chromosome number into two groups namely diploid and tetraploid. Karyotype suggests primitive or advanced feature of an organism.
A karyotype with large differences between the smallest and the largest chromosome of the set is known as asymmetric karyotype. Such karyotype is considered relatively advanced when compared with symmetrical karyotypes.
The degree of chromosome homology is studied from chromosome pairing during meiosis. This gives an idea about the relationship of parental species. Higher the homology, closer is the relationship between the two species. Some species have B-chromosomes which help in the identification of such populations.
Application # 2. Agriculture:
The contribution of genetics in the field of agriculture is remarkable in two ways, viz:
(i) In the improvement of crop plants and
(ii) In the improvement of domestic animals.
(i) Improvement of Crop Plants:
Various principles and methods of genetics have been applied for the development of plants useful to mankind. Controlled hybridization and artificial selection have increased usefulness of many plants.
Such applications include improvement in:
(i) Yield,
(ii) Quality
(iii) Maturity duration
(iv) Resistance to insects, diseases, salinity, drought, frost, lodging, etc. and
(v) Adaptability.
(ii) Improvement of Domestic Animals:
The usefulness of many domestic animals has been increased due to selective breeding. The milk production in cows and buffaloes, meat production in sheep’s, goats and pigs and egg production capacity in poultry have been significantly improved through the application of genetic principles. Moreover, many improved breeds of pet animals like horse, dogs, cats, pigeon and rabbits have been developed all over the world.
Application # 3. Medicine:
The advancements made in the field of genetics have been useful in the field of Medicine in two main ways as given below:
(i) Detection of Hereditary Diseases:
Now hereditary diseases can be detected at an early stage of life when it is possible to provide secondary cures in some cases. Refined techniques such as amniocentesis (foetus test) and foetoscopy have made such cures possible. Moreover, genetic diseases can be prevented by advising future parents with the help of family pedigrees.
(ii) Production of Antibiotics:
Special genetic strains of fungi and bacteria have been isolated to greatly increase the yields of antibiotics and other drugs. Besides these, genetics also helps in settling the disputed case of children through blood group studies.
Application # 4. Evolution:
Both natural and artificial selections have been responsible for evolution of various crop plants. However, selection is effective when sufficient amount of variability exists in the population in which selection has to be practiced.
Three genetic methods, viz:
(i) Polyploidy,
(ii) Introgression, and
(iii) Mutagenesis have played significant role in the evolution of various crop plants by inducing additional genetic variability.
New plant species like Triticale have been evolved through the application of genetical principles. Genetics has also helped in understanding the genetic origin of various crop plants.