Answer: The endocrine system sends chemicals called hormones through the bloodstream to change short-term and long-term activities in the body
Explanation: Endocrine system is a system made up of glands that produce and secrete chemical signal called hormones which travel through the bloodstream to the target cell where they exert their effects.
A hormone is a chemical messenger secreted by an endocrine gland. Long-term activities in the body influenced by hormones include growth and development.
Organism, population, community (first choice)
I hope this helped out, have a nice day! :)
I have only heard a few phrases for spine
Backbone
Vertebrae (vertebral column)
Spinal column
B, is the answer. I believe.
