The same receptor that responds to norepinephrine also respond to epinephrine, increasing the action of both. Adrenal medulla is NOT affected by the parasympathetic division of the autonomic nervous system (ANS
They are like that because they can't always be faulty and may have at least some spark of truth to this theory also as stated earlier a theory in scientific terms is just an observation so it can't really be turned down hence theory.
Nucleic acid is the answer for this problem
tress
plants
humans
bacteria
cells
grass
soil
animals
fish
insects
chicken
starfish
jellyfish
spider (or spiderman you never know)
lions
tigers
elephants
flamingo
chicken
sharks
crocodile
jellyfish
shrimps
roses
daisys
and soooooooo many more
Hey You!
I believe the correct answer to your question is: Endangered Species. (Also called threatened species).
I Really Hope This Helped You, Good Luck With Your Studies! =)