Final answer:
The theory of spontaneous generation suggests life can arise from nonliving matter, while the cell theory states that all living organisms are made up of cells and cells can only come from pre-existing cells. Spontaneous generation was disproven by scientists like Louis Pasteur, while the cell theory is a fundamental concept in biology.
Step-by-step explanation:
The largest distinction between the theory of spontaneous generation and the cell theory is that spontaneous generation suggests that life can arise from nonliving matter, while the cell theory states that all living organisms are made up of cells and cells can only come from pre-existing cells. Spontaneous generation was a long-held belief that dated back to Aristotle and the ancient Greeks, but it was eventually disproven by scientists like Louis Pasteur. On the other hand, the cell theory is a foundational concept in biology that explains the structure and function of living organisms.