DNA or should I say deoxyribonucleic acid is a double-stranded polymer of nucleotides that carries the genetic information of an organism and is found in the nucleus. DNA is replicated by the cell and controls cellular processes. Cells all have the same DNA but only some groups of genes are expressed while the others are inhibited. This ensures that the body produces the necessary cells, tissues and organs. Epigenetics is responsible for this; Epigenetic changes determine which proteins are transcribed by turning genes on or off, depending on the body's needs. It is non-coding DNA also known as junk DNA that contains key elements such as enhancers and silencers for transcription, allowing cells to regulate when and where to express “switch on” each protein and RNA. RNA transcribes the code to build whatever proteins the cell needs. Epigenetics is the answer to many questions that scientists have asked over the years regarding hereditary traits not found in DNA. There has been a lot of talk among scientists recently about how experiences in youth, such as trauma or stress, can contribute to mental illness. or addiction causing epigenetic changes to your genes. These epigenetic changes have the ability to turn genes on or off without altering the code within the DNA (just expressing certain parts of it). This change can chemically affect the activity of genes without changing the information in these genes. Epigenetic modifications can alter gene activity and how the brain responds to certain experiences. Many scientists, including Eric J. Nestler, think that these epigenetic changes, or as he calls them, epigenetic marks, are the reason why mental illness can be passed down from generation to generation... middle of paper... and through the sexual process. .Nestler said it perfectly: “Exposure to the environment and different experiences (including random events) during development and adulthood can change the activity of our genes and, therefore, how these traits manifest themselves . What researchers still don't understand is how and to what extent epigenetics influences our behavioral traits and susceptibility to mental illness, and whether such vulnerabilities can be passed on to future generations. Another mental illness, PTSD, has also been studied regarding epigenetics. Is it possible that second-generation survivors of the Holocaust or wars have higher levels of the stress hormone cortisol? If your parents suffer from the mood swings, irritability, nervousness and hypervigilance typical of PTSD, you will end up like this too??