They need an independent variable, in this case it should have been the fish food. Everything should be identical except the fish food, from what I read , it doesn't say anything about what type of food they used, or the dosage.
I think the answer is active transport
https://www.youtube.com/watch?v=EmPfjfmw_O8
B. synapomorphy
A synapomorphy is a shared apomorphy that distinguishes a clade from other organisms.
A clade also known as monophyletic group, is a group of organisms that consists of a common ancestor and all its lineal descendants, and represents a single "branch" on the "tree of life".
It will be
TTACTTATCGATCGAA
Hope it helped :)
