Low levels of estrogen is a sign that the ovaries of a woman are beginning to fail. This is a common occurrence when one is at menopausal stage. Estrogen and progesterone naturally decrease and eventually stops the menstrual cycle. Hope this helped.
B. bacteria that convert ammonia into nitrites and nitrates are found in the soil
This statement best demonstrates a way that the geo-sphere is involved in the nitrogen cycle.
A nitrogen cycle is defined as the movement of nitrogen between the atmosphere, biosphere, and geo-sphere in different forms. Ammonia is converted to nitrates by nitrifying bacteria in the soil. Then the plants absorb these nitrates from the soil and use these to build up proteins.
Answer:
materials move against a concentration gradient
Answer: [B]: "proteins" .
_________________________________
