The central vacuole is a cellular organelle found in plant cells. It is often the largest organelle in the cell. It is surrounded by a membrane and functions to hold materials and wastes. It also functions to maintain the proper pressure within the plant cells to provide structure and support for the growing plant.
There is no mixing of oxygen-rich and oxygen-poor blood.
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The right atrium and right ventricle of the human heart pump oxygen-poor blood to the lungs and the left atrium receives oxygen-rich blood. They never mix.
