
Prejudice against a race is essentially racism if it's overt, it's the very definition of it. Both individuals and groups can be equally guilty.
It should be redefined so you're allowed to think it, have a laugh with your mates, but you don't get branded unless you overtly show it. 99% of us have some form of prejudice.
Systemic racism is institutionalised racism only. It doesn't have to be perpetuated by the majority either. It depends who set the rules, they could just as easily be in the minority- Rhodesia, SA, Rwanda spring to mind.
Bigotry is a step up from prejudice, it's someone who overtly manifested his prejudice. If it was directed at someone because they were a different race then its the same as racism.