What are motor skills? You might hear about the development of fine and gross motor skills in the pediatricianâs office, parenting magazines or a baby development book. What exactly are they? This is actually a pretty complicated question.
The cell was first discovered by Robert Hooke in 1665 using a microscope. The first cell theory is credited to the work of Theodor Schwann and Matthias Jakob Schleiden in the 1830s. In this theory the internal contents of cells were called protoplasm and described as a jelly-like substance, sometimes called living jelly.
1838 Matthias Schleiden-First to observe and report that all plants were composed of cells. 1839 Theodore Schwann-First to observe and report that all animals were composed of cells. Theodore Schwann and Schleiden are attributed to the first two points of the Cell Theory.