Which of the following components is present in the troposphere?

Given below are two statements:
Statement $I$: Chlorofluorocarbons breakdown by radiation in the visible energy region and release chlorine gas in the atmosphere which then reacts with stratospheric ozone.
Statement $II$: Atmospheric ozone reacts with nitric oxide to give nitrogen and oxygen gases,which add to the atmosphere.
For the above statements choose the correct answer from the options given below :

Which gas is formed due to lightning in the atmosphere?

The structure of all living organisms on Earth is known as ............

Write a short note on the effect of Global warming and Greenhouse effect on environment.

What are the reactions involved in the ozone layer depletion in the stratosphere?