Answer:
The cell hypothesis by Schleiden and Schwann gave the proof and proposed that all the living being on earth are comprised of cells and cell is the basic or fundamental unit and practical unit of life. Moreover, the cell emerges from the previous cells was added by the Virchow to the cell hypothesis.
The cell hypothesis shows that whether a living being is tiny or a plainly visible giraffe as examined in the given question is made up of the major unit of life called "cell". The unicellular bacteria though the giraffe is multicellular.