Answer:
The question to be asked an investigated when observing a structure under the microscope to determine whether it is living is if it has a nucleus if eukaryote or nucleoid if prokaryote.
Explanation:
The major organelle that must be present in all living cells is the nucleus or nucleoid and the protoplasm. The observation of the cell under the microscope will show the subcellular entity, nucleus/nucleoid, more pronounced than other organelles in the cell. The nucleus house the necessary information for the maintenance and reproduction, which is mainly the genetic information that dictates the translational protein products that are needed to build another aspect of the cells. Therefore, when such a tiny structure is placed under the light microscope under the view of oil immersion, the nucleus of the cell should be visible if it is a living structure.
The blood circulates, so blood is reused constantly. There's no break in the circle, so it is a closed system
WIND ENERGY drives surface ocean currents
... termed "hypotonic," meaning less solids (or more diluted) than inside the cell. For fluid movement in/out of cells, water will diffuse (via osmosis) from the hypotonic solution to the hypertonic one, assuming a permeable barrier (i.e. cell membrane) allows it. With this case, water will flow into the cell from outside.
