The second one
One gene for a particular trait
c. It never changes during the experiment.
Archaea means ancient, bacteria are, well, minuscule organisms that live everywhere, and eukarya are organisms with cells that have a nucleus as well as membrane-bound organelles... my best guess if it is planets you mean, then the answer would be archaea, if it is plants, like flowers or such, then it is eukarya.
I hope this helps!
