Answer:
I think it's A: Sodium is needed to generate an action potential
Answer: They are all genetically tractable
Explanation:
Yeast, fruit flies, nematodes, mice or the small plant Arabidopsis have known genome i.e their entire genetic information is known to the scientific community, thus they are EASILY MODIFIED in genetic research.
Also, they are simple eukaryotes (having cells with defined nucleus) so they can explain the processes in the human eukaryotic cell during genetic research
Both reasons make them genetically tractable
Answer:A theory is and idea or belif that we belive to be true but there is still a chance it may be wrong
Explanation: Darwins ideas are called theories becasue though they are belived to be true as ttheir is science to back them up they are called theories because thereis a chance they might be false and they disagreed with religion i would compare Darwin the Einstien his theory of relaitivity is belived to be true but again we are not 100% sure hope this helps god bless