The answer is the G1 checkpoint
<span>The means is unknown. Filoviruses are known for causing hemorrhagic fever in humans. However, once a human is infected, passing the virus from person-to-person is the means by which others become infected. Most especially is the transmission through infected bodily fluids or objects that have been unsterilized and come into contact with those fluids.</span>
Answer:
The endomembrane systemis a group of membranes and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins.
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.
some one celled organisms reproduces by binary fission which is a process of cell division. The answer is 4.