21) The Three Major Regions of a Cell

The THREE major parts of a cell are: the plasma membrane, the cytoplasm and the nuscleus.
1) The Plasma Membrane- is a fragile barrier that is the outer boundary of a cell. The plasma membrane defines the extent of a cell, separating two of the body's major fluid compartments ( the intracellular fluid within the cells and the extracellular fluid outside the cells.
2) The Cytoplasm- is the intracellular fluid that is packed with organelles (the small structures that perform specific cell functions). The cytoplasm is the cellular material between the plasma membrane and the nucleus. The cytoplasm is the site where most cellular activities are accomplished. An electron microscope has revealed that the cytoplasm consists of three major elements: cytosol, cytoplasmic organelles and inclusions.
3) The Nucleus- controls cellular activities and contains DNA. The nucleus lies near the cell's center and also contains the instructions needed to build nearly all the body's proteins. The nucleus dictates the kinds and amounts of proteins to be synthesized at any time in response to signals acting on the cell.