Hopefully I can help with some of these:
Organism - A living thing
Control Center- Nucleus
Organ System - A group of organs that work together to perform one or more functions
Cell - the smallest structural and functional unit of an organism
Homeostasis - any self-regulating process by which an organism tends to maintain stability while adjusting to conditions that are best for its survival
I hope this helped out a bit. Sorry I couldn't do all of them