A ‘simple’ cell is nothing of the sort. Ernst Haeckel couldn’t have been more wrong when he called a cell a “homogeneous globule of protoplasm.” Since developing far more powerful microscopes than in Haeckel’s day, we have found that a cell is more akin to the tiny speck of dust in Dr. Seuss’ “Horton Hears A Who,” where the “speck of dust” turns out to be a tiny planet, home to a city called "Whoville,” inhabited by microscopic-sized inhabitants known as ‘Whos.’
A single cell is so complex, having many different compartments in which different tasks are performed---specialized areas partitioned off for specific jobs and duties---that it is much like an industrial city containing businesses, highways, departments of government, energy and utility companies, cargo storage, way stations, and sanitation engineers. The nucleus is where the DNA resides; the mitochondria produces the cell’s energy; the endoplasmic reticulum processes proteins; the Golgi apparatus is a way station for proteins being transported elsewhere; the lysosome is the cell’s garbage disposal unit; secretory vesicles store cargo before it must be sent out of the cell; and the peroxisome helps metabolize fats. Just as a house or building has rooms separated by walls or doors, each compartment is sealed off from the rest of the cell by its own membrane. Even the membranes can be considered separate compartments, because the cell places material into the membranes that is not found elsewhere. In fact, there is much more to the complexity of a cell than this little mini-summary has shown, but this will serve as a brief glimpse to demonstrate just one of the many reasons why the occurrence of macroevolution is astronomically improbable. In fact, Louis Pasteur disproved spontaneous generation (life arising from non-life), also called abiogenesis, in 1864.