Epigenetics

Epigenetics simply means something above or on top of the genetics. it involves the study of all the mechanisms that  changes the expression of genes by turning them switch on or switch off. the structure of gene is not altered but just turning the genes switch on or off changes the expression of genes.one such mechanism is methylation of DNA bases which prevents the expression of that DNA. the modification in his histone proteins of chromosome that tightly squeeze DNA in chromosome will prevent the expression of that DNA.the modifications in histones that relax the DNAwill allow the expression of DNA.it is due to epigenetics that skin cells are different from brain cells and liver cells. all of these cells have same kind of genes but in different types of cells different genes are switched on and switched off which makes these cells unique and different from others. our environmental also effects the turning on and off of genes for example when we spend more time in sunlight the amount of melanin increase in skin. what we eat also affects the turning on and off of genes. for example eating sugar rich diet cause more formation of  insulin.our mental stage also effects the turning on and off of genes .stress causes formation of cortisone hormone..for formation of cortisone specific genes are switched on. switch on and switch off of genes is a normal thing in body of all living organisms,but when this mechanism occur abnormally it results in diseases like cancer and Alzheimer.

By: Ashwani, bio-teacher ,Phagwara.