Some specific characters are found in the parents of each species. These characters are transferred from generation to generation through the process of sexual reproduction.
This process of transfer of specific characters of parents (called as parental traits) is called as Heredity. In biology there is a branch of study of heredity which is called as Genetics.
Genetics is the branch of biology in which heredity, micro mechanism of heredity, its impact and changes are studied.
Accumulation of variations through reproduction
Micro- actions that occur during reproductive processes and formation of embryo lead to changes in the next generation. This is the reason due to which sons and daughters are not the exact copies of their parents.
On the other hand they too remain quite different from each other. Thus lots of differences arise through generations during long period of time.
The changes that cause different members of each species and even sons and daughters of the same parents different from each other are known as variations.
Thus heredity and variations are two different forms of the same original process the sexual reproduction. The changes that occur during sexual reproduction lead to heredity and variations. Thus, we can say that genetics is the science of heredity and variations.
Physical basis of Heredity
The direct meaning of physical basis of heredity is – the physical structures through which incidents related to heredity are caused or through which parental traits are transmitted in the next generation.
It has been certified through modern researches that specific characters found in parents are transmitted into next generation and from generation to generation through sexual reproduction by three micro structures.
These micro structures are jointly found in the nucleus of each cell. These are technically associated with each other and each parental trait is transmitted through their coordinated activities. What are these micro structures?
Well, these micro structures are chromosomes, Deoxyribos Nucleic Acid (DNA) and Genes.
Knowing everything about these structures, developing technology for their manipulation etc. has led to the development of Modern Biotechnology. But to understand the physical basis of heredity properly we have first to know about the experiments and rules of heredity by Gregor Johann Mendel.
key words : heredity, biotechnology, Gregor Johann Mendel