AP BIOLOGY

Detailed explanation-1: -Cell theory, as formulated by Theodor Schwann in 1839, implied that this relationship was a specific and lawful one, i.e. that germs of a certain kind, all else being equal, would produce adult organisms of the same kind, and vice versa.

Detailed explanation-2: -The classical cell theory was proposed by Theodor Schwann in 1839.

Detailed explanation-3: -Light Microscopy and Cell Theory In 1833, Brown observed and described the nucleus, the first organelle. In 1838, the many and various observations were converted into a cell theory by Schleiden, who proposed that all plant tissues were composed of nucleated cells.

Detailed explanation-4: -First proposed by German scientists Theodor Schwann and Matthias Jakob Schleiden in 1838, the theory that all plants and animals are made up of cells marked a great conceptual advance in biology and resulted in renewed attention to the living processes that go on in cells.