I understand why threads are closed but the response I'm getting isn't really answering my question.

I've been asking if there is a way to tell the version of Backtrack I'm on, 4, 5, 5 R1...etc. I keep getting referred to 'man uname' which makes sense to check kernel version, but my question is whether the kernel version dictates the Backtrack version...is there a direct correlation? The second part of that question was if apt-get update && apt-get upgrade was the proper method to upgrade from 5 to 5 R1 and if so is that also the method to upgrade from 4 to 5 R1? Or is it preferred that you do a fresh install for one or both types of upgrades? I hope I'm not asking too much and based on my first thread I think others want to know these answers as well. I've looked everywhere and can't find a clear answer on these. Thank again in advance and sorry for the multiple threads....I wouldn't be creating new threads but my previous ones keep getting closed.