three domains , archae- 1st appeared, prokaria- not closed by nucleus and eukaria closed by nucleus
Answer:
Cell Division
Explanation:
Cells reproduce by the process of CELL DIVISION, which is the formation of an increased number of cells from a single parent cell. Mitosis is the type of cell division used for the multiplication of cells as it involves the synthesis of two identical number of daughter cells from a single parent cell.
However, certain drugs that may prevent the unregulated reproduction of cells is trying to directly affect the process of cellular division in that cell. This is because cell division is the way through which cells reproduce themselves.
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.
