Final answer:
The microscope played a crucial role in the invention of the cell theory by allowing scientists to observe cells for the first time. This observation led to the discovery of cells and their structures, laying the foundation for the cell theory.
Step-by-step explanation:
The microscope played a crucial role in the invention of the cell theory. The invention of the microscope allowed scientists, such as Robert Hooke and Antony van Leeuwenhoek, to observe cells for the first time. Through their observations, they discovered the existence of cells and their various structures. This led to the formulation of the cell theory, which states that all living things are composed of cells.