The molecular basis of inheritance explains how genetic material is transmitted from one generation to another. All living things inheriting DNA from their parent’s generation pass this DNA on to their offspring. This means that DNA is actually the hereditary material that are passed on from one generation to another and inherited by a subsequent generation as well. It is this molecular basis of inheritance that makes life so complicated for scientists and researchers.
DNA is the building block of life. It is made up of pairs of DNA bases called ‘complementary’ DNA that codes for amino acids or building blocks of RNA and protein, and DNA bases that code for sugars or rather more sugars that are used in transcription and replication. Every living cell reproduces its own DNA, this being the basis for the concept of mutation. Mutations can be caused by changes in the structure of DNA, which can affect its functioning.
Let us take an example to understand the basis of mutation in a more complex biological context. A bacterium P.Acnes is found within the body of a human and it develops a natural ability to adhere to and invade the surface of the skin of a human. Once it has established itself on the surface of a human, it begins to multiply causing a variety of different symptoms. As the number of P.Acnes increases it produces a set of proteins known as nitrobacteria. Nitrobacteria then begin to adhere to the skin and multiply. As a result of this nitrobacteria produces toxins which cause symptoms such as acne, boils in places where there are high levels of the bacteria.
Now let us look more closely at the molecular inheritance. When P.Acnes first enters the human body, amino acids are immediately produced from the germ cells (germs) which are part of the population of all cells in the body. The amino acids produced are then passed along to future generations, one of which is the germ cell that develops into a skin pore. The other germ cell that receives an amino acid from the skin and another one that synthesizes it, is also added to the family of germ cells. As new generations occur, each generation’s composition will differ from the last generation, but the overall genetic code will remain the same.
Now that we know the basis of mutation, we may see how important it is to understand it. The molecular basis of inheritance is how information is transmitted between generations. For instance, during reproduction, eggs are passed on from mother to daughter. This process occurs through genetic information passed along by genes. The genes themselves are nothing more than sets of instructions which can be passed on from parent to child.
To better understand the molecular basis of inheritance, it is important to understand the molecular basis of DNA. The genetic information that is passed down is enclosed within the double helix structure of DNA. The base of this double helix is amino acids which are the building blocks of proteins. Every living cell, whether animal or vegetable, possesses DNA which contains genetic information.
The DNA is a linear structure and consists of two bases, A and C, with each base pair consisting of a string of bases that are complementary to both bases. The ends of the strings of bases, called pairs, form a triple helix structure. The bases of this triple helix structure contain genes that instruct the body how to build and develop new proteins. The base pairs that form the base pair structure are referred to as transcripts.
Transcription occurs when new DNA is copied from DNA within the cells of the body. This copying occurs via a mechanism known as transcription initiation reaction (TIR). This reaction is initiated by the binding of a transcription control enzyme to DNA in the genes of the cells. The molecular basis of inheritance then determines whether or not the genes will be expressed in all cells of the body or only in a selected tissue or organ.