From what ever key you start a minor or major pattern, the the pattern with all its steps and half-steps has to remain exactly the same. For that reason black keys come into play and flats or sharps have to be used to lower or raise the key by a half step. It is important to remember that one scale can only include flats or sharps as key signature.
Tonality is a group or a row of notes that has a fixed interval based structure. Tonality has got a note sounding as a center of the musical material. It is the root note of the tonality. Tonality is related with a certain key and has its name after that key. There are major and minor tonalities for example.