The answer to this question would be: vitamin
Some bacteria can produce vitamin K2 in the intestine. Other bacteria also able to change vitamin K1 into vitamin K2. But the amount produced is not much, so human still need to fulfill it from the diet. Vitamin K has a role in calcium regulation and in blood clotting pathway.
<span>The correct answer is "Absorption of rainfall by soil."
The hyrdosphere refers to all water on the earth's surface. The geosphere, in this context, refers to the solid parts of the earth (rocks, sand, etc.) Since rain is part of the hydrosphere and soil is part of the geosphere, rain soaking into the soil would be an interaction between the two. The other choices deal with changes in the hyrdrosphere, but there is no interaction with the geosphere.</span>
...The origin of life on Earth is a set of paradoxes. In order for life to have gotten started, there must have been a genetic molecule.. something like DNA or RNA—capable of passing along blueprints for making proteins, the workhorse molecules of life.
