Question

1. Which of the following was Rudolf Virchow's contribution to our understanding of cells?

Cells are the basic units of life.
All living things are made of cells.
Cells can be categorized as either prokaryotes or eukaryotes.
All cells are produced from existing cells.

Answer 1

Out of the following, Rudolf Virchow's contribution to our understand of cells is that all cells are produced from existing cells. 

Answer 2

The correct answer is this: ALL CELLS ARE PRODUCED FROM EXISTING CELLS.
Rudolf Virchows was a doctor and scientist of German origin. He was the first scientist to apply cell theory to mechanism of diseases in humans, this aspect of medicine is called pathological processes. Through his research, he discovered that new cells are always produced from existing cells.