These findings led to the formation of the modern cell theory, which has three main additions: first, that DNA is passed between cells during cell division second, that the cells of all organisms within a similar species are mostly the same, both structurally and chemically and finally, that energy flow occurs within cells. Since the formation of classical cell theory, technology has improved, allowing for more detailed observations that have led to new discoveries about cells. The third part, which asserts that cells come from preexisting cells that have multiplied, was described by Rudolf Virchow in 1858, when he stated omnis cellula e cellula (all cells come from cells). These parts were based on a conclusion made by Schwann and Matthias Schleiden in 1838, after comparing their observations of plant and animal cells. The second part states that cells are the basic units of life. The first part states that all organisms are made of cells. The classical cell theory was proposed by Theodor Schwann in 1839. Cells are the basic unit of life the microscopic building blocks from which the human body as well as the animals, insects and plants are constructed. This discovery led to the development of the classical cell theory.
Robert Hooke suggested the name ‘cell’ in 1665, from the Latin cella meaning storeroom or chamber, after using a very early microscope to look at a piece of cork. It is the smallest unit capable of independent reproduction.
While looking at cork, Hooke observed box-shaped structures, which he called “cells” as they reminded him of the cells, or rooms, in monasteries. A cell is the basic unit of life as we know it. The invention of the microscope led to the discovery of the cell by Hooke. In 1665, Robert Hooke published Micrographia, a book filled with drawings and descriptions of the organisms he viewed under the recently invented microscope.