Genetics





What is genetics?

The branch of science that deals with the process of inheritance of characters and their variations among the related organism is called genetics. Variations are the differences that occur among and within species. Variations of heredity are present in the offspring of the same parents as well as in the offspring of different parents, that is, these variations are inheritable. So it may be said that the inheritable variations are the raw materials of evolution. So, we may say that the science of heredity, dealing with resemblances and differences of related organisms resulting from the interaction of their genes and the environment is the genetics.




Idea on Genetics

At the living world every plant and animal are maintaining their race through creation of new individuals by the process of reproduction. It is known to us that new individuals show similarity to their parents. So it can be said that, the characteristic features of each species are transmitted to their offspring from generation to generation. As for example the offspring of fake cow looks like a cow. Mango trees are developed from the seeds of Mango only. Offspring of a main maintains the traits or characteristics of man and it never keeps any long impression about similarities with other animals. That is the matter of genetics.

Thought of Variations

From the ancient time man has noticed that the characteristics of the parents had expressed in the progeny, because the parents and their progeny are deeply attached to each other. Fusion of sperm and ovum of the parents, gives rise to a zygote and zygote develops into a matured individual. So, it can be said that the characteristics of the parents are transmitted to the offspring who they are gametes. But it is known to all that the offspring never show the exact similarity with their parents. Though the fundamental similarities in structural and physiological functions are present in the offspring of the same parents or among the same species, yet the differences are also commonly observed. These differences in the living organisms are called variation. In heredity these variations are playing a vital role. But it should be remembered that the variations due to environment are just temporary and is temporary variations have nothing to do with the next generation. The study of genetics deals all about these. It should be kept in mind that the hereditary variations among the offspring of the same parents are mainly present in sexually reproducing organisms. These variations are transmitted from one generation to next generation and so on.



Concept of Mendel

G. J. Mendel

G. J. Mendel

But there was lack of scientific concept about the heredity before the Mendel age. The first scientific concept on genetic inheritance came from Gregor Johann Mendel in the middle of the 19th century. G. J. Mendel was an Austrian monk and he joined the Augustanian Monastery at Brunn in Austria. Though he was a monk yet he developed the scientific attitude is because he had his education with science. Mendel made his hybridization experiments in the garden of the Monastery. He conducted the hybridization experiments on a garden of peas.
In the Natural History Society at Brunn Mendel Delhi hurt lectured in 1865 on his experimental results in garden pea. But at that time the biologist of the world failed to give the due importance on his classical paper during his lifetime. In the year 1900 three biologist, such as Hugo de Vries of Holland, Eric von Tschermak of Austria and Carl Correns of Germany worked independently but came to the same conclusion as Mendel. These three biologists rediscovered the Mendel’s law of inheritance. A younger branch of biology established in 1900 is the genetics. Since then Mendel is considered as the pioneer of modern genetics. He is now regarded as the father of genetics. A third application of Mendelian principles to both plants and animals modern biologist have realized importance of the laws of inheritance as deduced by great Mendel.

What is Mendelism?

Mendel’s hybridization experiments, analysis of the experiments and formation of laws of inheritance are all collectively known as Mendelism.