Oxygen-poor blood enters the heart through the right atrium. From there blood flows through the tricuspid valve into the right ventricle. When the heart contracts during the diastolic phase, this blood is pumped out through the pulmonary arteries that run toward the lungs. At the lungs, the blood is circulated through a series of progressively smaller arterioles until it flows through capillaries lining the lungs' alveolar sacs. It is here that gas exchange takes place as oxygen is taken up by the blood, and carbon dioxide is released into the waste air.After oxygenation, the fresh blood is circulated back through the bronchial veins and into the pulmonary veins. These run from the lungs and drain into the heart's left atrium. During the systolic phase of the heartbeat, the mitral valve under the left atrium opens and permits blood to pass into the left ventricle. This chamber is heavily muscled and it has the power to pump the oxygen-rich blood out through the aorta and into the rest of the body.
B replaced because it takes place when water dissolves the original hard parts and replaces them with mineral matter.
Carbon is found in the atmosphere mostly as carbon dioxide.
A design of growth in which (occurs only in a different situation), the population frequency of an organism rises gradually originally, in a good acceleration time, later progresses swiftly nearing an exponential growth pace just like the J-shaped curve, however, it later declines (meaning rejects) in a bad acceleration time till at zero growth rate the population maintains. For example, yeast is a tiny fungus, so tiny, a microscope is required to view it, furthermore, it is used to produce bread and alcoholic drinks, displays the traditional S-shaped curve if raised in a test tube. Its maturity levels off as the population deplete the nutrients that are essential for its growth.
