Answer:
Calcium
Explanation:
Parathyroid hormone (PTH) is a hormone that is secreted by the parathyroid gland. It is the major regulator of the plasma concentration of calcium ions. It regulates calcium ions in the kidney, intestine and bones.
In the kidney, is involved in the re-absorption of calcium in distal ducts and the renal collecting duct, it is also involved in activating the conversion of 25-hydroxy vitamin D into 1,25-dihydroxy vitamin D (calcitriol).
In the intestine, PTH is involved in the absorption of calcium, by increasing vitamin D production.
In the bone, it helps in regulating calcium levels; when serum calcium level is low, PTH stimulates the activity of the osteoclast, to produce more calcium.
Answer:
carbon and three oxygen atoms
Answer: bc any living organism must take in energy via food, nutrients, or sunlight n order 2 carry out cellular processes.
Explanation: The transport, synthesis, n breakdown of nutrients n molecules n a cell require the use of energy.
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A control is a experimental variable that is kept constant or unchanged during an experiment. During a controlled experiment, the controlled variables are held constant to minimize or stabilize their effects on the subject, its unchanging state allows the relationship between the other variables being tested to be better understood.