History of the formulation of cell theory:

In the history of biological Sciences, ancient Greeks were the first to make comprehensive attempts to organize the data of the natural world. Aristotle presented organized observations to support the idea that all animals and plants are somehow related. Later this idea gave rise to questions like “Is there a fundamental unit or structure shared by all organisms?” however, before microscopes were first used in the 17^th century, No one knew with certainty that living organisms do share a fundamental unit i.e. cell.