Final answer:
The invention of the microscope was essential for observing cells, enabling scientists to visualize cellular structures starting with the light microscope and later with more detail through the electron microscope.
Step-by-step explanation:
Discovery Essential to Observing Cells
The technological advancement necessary before scientists could begin to observe cells was the invention of the microscope. The invention of both the light microscope and later the development of the electron microscope were pivotal. Robert Hooke's use of the light microscope in the 1600s allowed initial observation of cells, although by the late 1800s, light microscopes reached their limits in terms of magnification and resolution. However, the advent of the electron microscope in the 1950s enabled scientists to visualize even smaller cellular structures and fundamentally changed the study of biology by allowing for the observation of organelles and other minute features within cells.
To view individual components within cells using a light microscope, scientists commonly employ special stains to enhance contrast. These stains enable the visualization of structures that would otherwise be difficult to see due to the translucent nature of most cellular components.
The basic unit of life is recognized as the cell. Without the invention and subsequent enhancements to the microscope, our understanding of cells and the subcellular structures would remain obscured.