-
He was the first one to invent the first compound microscope.
-
Jan Baptist van Helmont studied how plants grew and reproduced.
-
Robert Hooke discovered a honey-comb-like structure in a cork slice using a primitive compound microscope. He only saw cell walls as this was dead tissue. He coined the term "cell" fro these individual compartments he saw.
-
Anton Van Leeuwenhoek saw and described bacteria, and consideredthe first to observe single-celled organisms known as Prokaryotes
-
Lorenz Oken believed in the cell theory, but he had his own ideas about it. He believed that there were tiny units of life called infusoria that make up the human skin, bones, and organs.
-
Robert Brown, an English botanist, discovered the nucleus in plant cells.
-
Matthias Schleiden, a German botanist, discoverd all plants were comprised of cells.
-
He reached the conclusion that not only plants, but animal tissue as well is composed of cells. This ended debates that plants and animals fundmentally different in structure.
-
Albrecht von Roelliker discovered that sperm and eggs are also cells.
-
Rudolf Virchow added the 3rd part of the cell theory. As all cells develop only from existing cells. Virchow was also the first to propose that diseased cells come from healthy cells.
-
He performed additional experiments on soup employing filtered air and flasks with straight necks and long S-shaped necks. He discovered air-borne microbes were able to infect the broth in regular flasks but bacteria settled at the top of the curve in the S-shaped flasks, leaving the soup affected.
-
He theorized how animals and plants were developed. Later in life got arrested for it.
