Ventricles need more, denser muscular tissue because they pump blood to either the whole body(aorta) or to lungs(pulmonary artery). Atria on the other hand pump blood straight to the ventricles so they do not need as much force and power to pump the blood.
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Cytoplasm of the cell and yields a small amount of energy .
Answer:
Gravity draws the matter in an interstellar cloud together to form a star.
Answer:
To conversion of light energy into chemical energy stored in organic compounds (sugar).