It can either support the topic or a point which you are making. For example
Whilst the non-standard orthographical representation of the the lexical item 'lose' as 'loose' may be acceptable in less formal contexts such as internet chat rooms and social networking websites, it is less likely to be tollerated in formal prose as it creates ambiguity of meaning, hence why linguist David Crystal notes that 'standard English spelling is an absolute criterion of an educated background.'
Edit: Oh sorry, I have misinterpreted. It really depends. If the quote is literally infused within the question, then you must relate your essay to it.
However if it is more of a stimulus quote, then it is just an idea which you could base your essay around. Always good to integrate quotes somewhere into your essay though, even if you have to oppose them.