As all we know about recently infectious disease Covid-19 spread out all over the world. My locality was not out of this disease as usual. In my locality, covid-19 took a devastating shape and many of our locality were infected by this disease. I live in an apartment of 5th floor and in all floors, there was at least one covid patient. This disease was mainly caused by a virus named corona virus and this virus included mutated gene. The gene was able to change its DNA.