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Who proposed cell theory?

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biology; microscope — Biology A researcher using a microscope to examine a specimen in the laboratory.

Cell theory was first proposed by German scientists Matthias Jakob Schleiden and Theodor Schwann in 1838 and 1839.12

Schleiden, a botanist, initially formulated the principle in 1838 by stating that all plant parts are composed of cells or their derivatives. Schwann, a physiologist and friend of Schleiden, subsequently extended this concept to include animals. Together, they established that cells are the fundamental units of structure and function in all living organisms, effectively bridging the fields of botany and zoology.321

While earlier figures like Robert Hooke and Antonie van Leeuwenhoek made significant early observations of cells using the microscope, it was the work of Schleiden and Schwann that formally defined the cellular basis of biological life.12