Question

What would happen to life on Earth if the ozone layer was not present?

Answer 1

UV radiations by the sun reach on the earth and harm every single body.
Shortly, nobody would exist without ozone layer.

Answer 2

if the ozone layer did not exist "not present" then all life on earth as we know it would die. This is because the sun is constantly giving powerful energy giving nice warm Energy. The earth would be really cold without it.