∙ Cell membrane is the outermost layer of the animal cell. It controls the movement of substances in and out of cells. It is a selectively permeable membrane.
∙ Cytoplasm is the jelly-like fluid substance that fills the cell.
∙ Mitochondrion is the double membrane-bound organelle. It generates energy in the form of ATP.
∙ Nucleus is the membrane-bound organelle present in the eukaryotic cell which stores the hereditary material and controls the overall activity of the cell.