 Now, we come on the mechanism of gene action, how the genes they act, how they perform their functions, what are the functions of the genes basically. Replicate itself we call it replication making its own copies, it occur during the cell cycle, the synthesis phase of cell cycle when before division, before cell division because we know that after mitosis the cell one cell the parent cell will be divided into two daughter cells. And the daughter cells should have an equal quantity of DNA as it was present in their parents. So, before entering into the division phase the DNA the genetic material have to replicate themselves make the their own copies which have same structure and quantity. So, one function is replication the other function is transferring the information or encoding the information present in them in the form of proteins. And this function of the DNA it performs it by two processes going side going one by one one is called the transcription. Transcription is actually making an RNA molecule out of a DNA molecule that is DNA molecule act as a template with the help of that a complementary strand of RNA is produced. Then this RNA in the zoo carriers have to go out of the nucleus and encode for a protein. Protein may make the hairs proteins may make the our nails proteins may make any of the cellular structure may be a membrane protein may be an enzyme or anything. This process from RNA to protein is called the translation. So, this is another function of DNA that is transcription making an RNA molecule and translation making a protein from an RNA. The replication is the doubling of DNA replication occur in a specific time when the cell have to divide. But the transcription and translation these are the ongoing processes all the time occurring in the cell. Whenever cell need to make an enzyme cell need to make a many of its structures a receptor or anything any structural part it have to go by the process of transcription and translation. Then there is another related term called genetic code or codon three nucleotides in the DNA codes for N amino acids as we know that proteins consist of amino acids. Amino acids are the basic units of proteins amino acids join together to make protein. And three nucleotides combine together codes for an amino acid we call this genetic code or codon. So, a codon is a triplet code that codes that instruct the production of N or we can say attachment of an amino acid to a peptide chain. Then transcription if just we have a brief look on a diagram this could say that transcription is from DNA to an RNA molecule this particular RNA molecule is called a messenger RNA. So DNA to messenger RNA is called transcription then messenger RNA to protein is called translation that is the language of DNA is translated by the messenger RNA into the protein. We call it central dogma of molecular biology or molecular genetics. Central dogma means that there is in any field of study we have a central theory we have a central idea around which all of that science revolves. This is the central dogma of molecular biology or a genetics that DNA codes for RNA transcription RNA codes for protein translation.