Pardon? I don’t understand the question
The beginnings of a brain first become apparent around four weeks after conception when the neural plate folds to form the neural tube
The answer to the very question you are asking is "plants"
Answer:
Calcitonin stimulates the kidneys to absorb calcium when calcium levels are too low, while parathyroid hormone stimulates the kidneys to excrete calcium when calcium levels are too high.
Explanation: