Blood enters the heart at the right atrium. The right atrium contracts, forcing blood through the tricupsid valve into the right ventricles. Then the right ventricles contracts, pushing the blood through the pulmonary semi-lunar valve into the pulmonary artery. The pulmonary artery transports blood from the lungs, receiving oxygen. Then, pulmonary veins take the oxygenated blood to the left atrium. Blood is then forced through the bicuspid valve into the left ventricles. The left ventricles is the major pump that sends the blood out to the body. The left ventricles contracts sending the blood through the aortic semi- lunar valves and into the aortic. The aortic and its branches carry the blood to all the tissues (including fingertips) of the body. Veins take the deoxygenated blood from these parts of the body back to the heart- to the superior and interior vena cave and into the right atrium.
Answer:
individuals that develop beneficial traits have a better chance of survival, and are then able to pass on their genes. Eventually, if enough of those genes are passed on, that gene will become more prominent within the population.
Answer:
B. isolation by vicariance
Explanation:
Vicariance is one of the biological processes that cause the isolation of a population of a species by a geographical barrier. These geographical barriers such as river, valley, causes physical physical isolation of organisms. Over time, these subpopulations of the ants that are separated by flood, undergo speciation to form new species.
Rivers and oceans may have been prominent features in its early history billions of years ago Mars was a warm and wet world that could have supported microbial life in some regions but the planet is smaller than earth with less gravity anything or atmosphere overtime as liquid water evaporated more of it escaped into space along less to fall back to the surface of the planet.
hope this helps
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zane
The relative balance within an optimal range also known as homeostasis