Genetics is a scientific field that deals with genes – their molecular structure and function, their expression and occurrence in populations, connection to heredity, and the study of the relationship among organisms.
Who and what we are is primarily determined by our DNA. The DNA is essentially present in the nucleus (core) of every cell of our body. It determines our appearance, how we respond to environmental factors (e.g. sunlight, nutrients, physical activities) and, to a certain extent, our behaviour too.
Our DNA is unique – comparable to a fingerprint. In the whole world, no two persons (except identical twins) have identical DNA.