Significant Events in Biology

Discovery of Microorganisms

Jan 1, 1674

Anton Van Leeuwenhoek accidently discovered microorganisms by examining a drop of water with a microscope.

Discovery of Photosynthesis

Sep 23, 1770

Jan Ingenhousz observed and found that plants react differently when exposed to sunlight compared to darkness.

Discovery of the Cell Nucleus

Sep 23, 1831

Robert Brown discovers the nucleus within cells.

Discovery of Cell Division

Sep 23, 1879

Walther Flemming observes animal cells dividing in stages he called mitosis.

Discovery of Sex Cells

Sep 23, 1884

August Weismann discovers sex cells when observing that they divide differently than regular cells.

Discovery of Mitochondria

Sep 23, 1894

The first recording of intracellular structures were found in the 1840s. Only until 1894, Richard Altmann established them as cell organelles.

Discovery of Hormones

Sep 23, 1903

William H. Bayliss and Ernest H, Starling discover chemical messengers known as hormones

Discovery of the Krebs Cycle

Sep 23, 1937

Hans Kreb identifies the Kreb Cycle as the steps the cell takes to create energy from sugars, fats, and proteins.

Discovery of Archaea

Sep 23, 1977

Carl Woese discovers that there more types of bacteria. Prokaryotes were not the only simple celled organisms on Earth.

First to derive stem cells

Sep 23, 1998

James Thomson and a group of scientists were the first to derive human embryonic stem cells.