Name the layer of the atmosphere that is associated with ‘good ozone’.

OR

Mention the term used to describe a population interaction between an orchids growing on a forest tree.

Ozone in the stratosphere protects us from harmful UV radiation.

OR

Orchids growing on the tree exhibits commensalism. The orchids get the benefit of sunlight as they grow as epiphytes. The forest tree remains neutral with no advantage or disadvantage.