(ii) 1) Ozone layer is present is stratosphere of atmosphere.
2) It is helpful for living organisms as it prevents Ultraviolet light to reach on earth which is very harmful.
(3) Ultraviolet light is harmful for living organisms as it breaks chemical bonds in DNA and protein, thus causes mutation.
4) Ultraviolet light exposure occurs to mainly skin so causes skin cancers like melanoma, squamous cell carcinoma.
5) Ultraviolet light causes inflammation of cornea known as snowblindness cataract.