What will happen, if ozone gas is present in atmosphere?

cbse
natural-resources

#1

What will happen, if
(i) ozone gas is present in atmosphere?
(ii) all plants become extinct from the Earth?


#2

(i) If ozone gas is present in atmosphere, then living organisms cannot survive because it is highly poisonous gas and harmful for living organisms.
(ii) We will not be able to survive on Earth, if all plants
become extinct because plants are the only source of oxygen in the atmosphere.