Ozone is know to cause respiratory problems in humans and damage plants. however, the ozone layer provides protection for earth. explain where ozone is found, what it does, and what causes its depletion. : ) plz answer

Ozone is mainly found in two regions of the Earth's atmosphere. Most (90%) are found in stratosphere and some (10%) are found in troposphere.  

The ozone layer protects the DNA of all surface dwelling life, by absorbing UltraViolet-B from our Sun. 

It is caused by the release of chlorofluorocarbons (CFCs), hydrofluorocarbons (HCFCs), and other ozone-depleting substances (ODS), which were used widely as refrigerants, insulating foams, and solvents.