Teori mozaik wilhelm roux experiment

DEVELOPMENTAL BIOLOGY 3230History and Basic Concepts, Principles of Development pg. 1-29Aristotle suggested that embryos were either preformed in the "embryo" and just grew in size, or they formed from something simpler via epigenesis.

For religious reasons many wanted to beleive that all embryos were created with and contained in the first "man".

Teori mozaik wilhelm roux experiment pdf

The earliest microscopists drew pictures such as the one at left suggesting that they could see the preformed embryo in the head of the sperm. This preformation idea was laid to rest with the advent of better microscopes and the growing evidence that all animals are made up of cells. The Cell Theory (1820-1880) advanced by Schleiden and Schwann proposed that all animals were communities of diversely functioning cells.

The egg was identified as a single large cell and observed to divide during embryogenesis.August Weismann in the late 1800s put forth the theory of germ plasm.