The answer is C. nitrogen.
Plants are main producers in ecosystems so, primary productivity of ecosystems depends on them. Carbon is necessary for plants, but it is widely present in plants. On the other hand, calcium and sodium are not as essential. However, nitrogen is important for plants because it is necessary to make proteins. Proteins take part in many different processes such as photosynthesis (this is actually primary productivity). But, nitrogen is not available to plants, they cannot absorb it simply from the air but rely on some symbiotic bacteria which are able to.
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Answer:</h2><h3>1. four</h3>
Your heart has four separate chambers that pump blood, two on the right side and two on the left.
2. When the ventricle relaxes, the aortic valve closes <em>to prevent blood from flowing back into the ventricle</em>. When the aortic valve is not working properly, it can interfere with blood flow and cause the heart to strain to send blood to the rest of the body.
3. In medicine, a person's pulse is a pressure wave caused by the expansion of the arteries as a result of the circulation of blood pumped by the heart.
4. Capillaries are tiny vessels that branch out from arterioles to form networks around body cells.
Capillaries are very tiny blood vessels — so small that a single red blood cell can barely fit through them.
<em>hope</em><em> </em><em>this</em><em> </em><em>help</em><em>!</em><em> </em><em>^</em><em>^</em>
Explanation:
group b. is called the control group. it is important to compare the 2 groups for any similarities. this determines if the medications in group a are working like intended. to keep track of side effects w/group a..
Answer:
If the calcium levels in blood increases, then there is increase in blood glucose level.
Explanation:
Calcium in blood plays a vital role of homeostasis in regards to level of secretion of insulin. If the calcium level is altered, the homeostasis mechanism is hampered. Several researches have shown that alteration of serum calcium level affects the metabolism process of carbohydrate and makes the person vulnerable to risks of diabetes mellitus and associated complications. Hence during calcium supplementation, the person's blood glucose level must be considered.