He also pulled together and organized previous statement on cells into one theory, which states: 1 - Cells are organisms and all organisms consist of one or more cells 2 - The cell is the basic unit of structure for all organisms: 1840: Where does life come from Albrecht von Roelliker discoveres that sperm and eggs are also cells. 1845
Nov 05, 2007 · 1833 – Brown descibed the cell nucleus in cells of the orchid. 1838 – Schleiden and Schwann proposed cell theory. 1840 – Albrecht von Roelliker realized that sperm cells and egg cells are also cells. 1856 – N. Pringsheim observed how a sperm cell penetrated an egg cell.