The answer is vitamin D. This is actually a group of vitamins of similar molecular structure responsible for facilitating increased absorption of calcium, magnesium and phosphate from the gut. The most important of the vitamin D compounds are vitamin D3 and D2. While vitamin D can be obtained from your diet and supplements, the major source of vitamin D is from a chemical reaction dependent on skin exposure to the sun.
The oxygen cycle can be found in all but the geosphere. There's oxygen in the atmosphere, so it has to be there, and the biosphere includes living things, which breathe oxygen, and water (hydrosphere) is made up of partly hydrogen, so there has to be oxygen there as well.
Answer:
why are you under water lol
and also try to swim eh?
The correct answer here is C. A molecule that has both polar and
nonpolar regions is called ampipathic. The polar end of the molecule is
water-loving, or hydrophilic, and the nonpolar end of the molecule will
be water-repelling, or hydrophobic. This means the molecules are able to
connect both to other water molecules, and to molecules of other
substances.
