Answer: A
Explanation:
Oxygen makes up another 20 to 21 percent of our atmosphere. It's essential for life on Earth, and interestingly enough, it is poisonous when highly concentrated. Our concentration of 20 to 21 percent seems just right.
The egg came first this was found out In July 2010
Answer: ecosystem
An ecosystem is a community of living and non-living components. A coral reef is an aquatic ecosystem which is formed by a continuous walls of calcium carbonates released by living animals they get combine to form rocks. These rocks and walls are collectively called as hard stony corals. These hard stony corals provide shelter to many aquatic animals like fishes. As the water is the chief abiotic factor along with coral walls and rocks which help in the survival of living organisms therefore, ecosystem is the largest organizational level found in one coral reef.
Answer:
Explanation:
Aldosterone is a hormone which is produced by the adrenal glands which are present above the kidneys. The role of aldosterone is to regulate the blood pressure. It causes the reabsorption of water and salts into the bloodstream during the kidney filteration process. Hence, maintains the blood volume, restors blood pressure and salt level.
Renin is an enzyme. It facilitates chemical reactions which stimulates the synthesis of angiotension II, it directs the synthesis of aldosterone.
Answer:
Arteries
Explanation:
There are three main types of blood vessels: veins, arteries, and capillaries. Arteries are the blood vessels that carry the oxygenated blood from the heart to various body parts. Veins pick the deoxygenated blood and deliver it to the heart to be oxygenated.
Arteries are the blood vessels with thick walls and no valves. Blood is pumped with higher pressure from the heart into arteries. The pulmonary artery is the only exception that carries deoxygenated blood from the right ventricle to the lungs for oxygenation.
