They are called the chief cells. These cells are found in the parathyroid gland. they produce PTH and increase Ca2+ levels. These are small round cells with a central nucleus. PTH is antagonist to calcitonin which reduces Ca in body. Parathyroid glands found on the posterior surface of thyroid gland. There is a superior/inferior one. They are made up of chief and oxyphil cells, the chief cells produces the parathyroid hormone while the oxyphil cells no one knows what they do.
The answer would most likely be sodium because carbon is a plants food, phosphorus is a nutrient in soil, hydrogen is air, but sodium does not have a place in a plant:)
