Zacharias Janssen ~~~~~~~~~~~~~~~~~~~ Born in Netherlands in between 1580-1588, he created the first optical telescope. He is also credited, with the help of his father, for the first compound telescope.
Robert Hooke ~~~~~~~~~~~~~~ Born in England in 1635, he was the first person to discover a honey-comb like structure in a piece of cork. He named it a cell since it reminded him of Monk's rooms.
Anton van Leeuwenhoek ~~~~~~~~~~~~~~~~~~~~~~~~~ Born in Netherlands in 1632, he was the first person to discover bacteria. He was looking at a bit of gunk from his teeth when he noticed little things that looked like animals. He named them animalcules
Robert Brown ~~~~~~~~~~~~~~ Born in the UK in 1773, he discovered the nucleus in plant cells. He also discovered its purpose and went on to prove the statement, "All cells come from preexisting cells."
Theodor Schwann ~~~~~~~~~~~~~~~~~~ Born in Germany in 1810, he first stated that plant tissues and animal tissues are made of cells. After that, concluded that all tissues are made of cells.
Rudolf Virchow ~~~~~~~~~~~~~~~~ Born in Poland in 1821, he was the one that formed the whole cell theory. He used the work of other scientists to form this: "All living organisms are composed of one or more cells, the cell is the basic unit of organization and structure in organisms, and that all cells come from preexisting cells.