Genetics refers to the study of genes to understand how living beings inherit certain hereditary characteristics. It is crucial to understand how genes work to understand why each organism in a species is different from one another. In human beings, it explains the presence or absence of traits or why we inherit certain characteristics from our ancestors. Genes are made of DNA and RNA. In a high-end organism like humans, they basically decide everything – eye colour, blood type, skin colour, height, susceptibility to diseases, behavioural traits and many other things. They also play a vital role in explaining how all the species evolved on this planet.