Do you NEED any of them? Unless you are trying to correct a problem you are experiencing, I.E. something doesn't work, or is not supported by your current BIOS, you don't NEED to update anything. As a general rule you should only update a BIOS to correct an issue you are having, not just to get the "latest & Greatest" BIOS.
That being said, if you ARE going to update your BIOS, then (in your example) going to 1.2 should give you everything that 1.1 had. You should be able to go from 1.0 directly to 1.2 without having to install 1.1.