Name __________________________
Date ___________ Period_________
The Cell Theory
Key Concept: The cell theory states that
All living things are made of cells.
Cells are the basic units of structure and function in living things.
Living cells come only from other living cells.
Directions:
Complete the following passage by filling in the correct missing words or
phrases.
A cell is defined as ___the basic units of structure and function in living
things___. Cells were first described by the English scientist ___Robert Hooke___, who
thought that they resembled the tiny rooms, or cells, where monks live. Actually,
___Hooke___ did not see living cells, just the ___cell walls___ of dead cork cells. Cells
contain structures called ____organelles___. This term means tiny ___organs___.
The discovery of cells and their internal parts was made possible by the invention
of the ___microscope___ in the ___late 16th___ century. This was around the same
time as the English Bill ___of Rights___. During the next two hundred years, the work
of many scientists led to the development of the ___cell___theory. This theory can be
summarized by three statements:
1. ___All living things are made of cells___
2. ___Cells are the basic units of structure and function in living things____
3. ___Living cells come only from other living cells____
Describe how each of the following scientists contributed to our knowledge of cells, including
the year of their contribution. On the back of this sheet, construct a timeline including the
scientists and their contributions, Columbus sailing for the New World, the English Bill of Rights,
the signing of the Declaration of Independence, the French & Indian War, our War for
Independence, and Lewis and Clark exploring the American West.
1. Zacharias & Hans Janssen ___Developed first microscope 1590___
2. Robert Hooke ___coined term “cells” Published Micrographia 1665____
3. Anton van Leeuwenhoek ___Improved microscope. Looked at blood, rainwater,
and scrapings from his teeth 1674____
4. Mathias Schleiden ___co-founder of cell theory – 1st and 2nd statements 1838___
5. Theodor Schwann ___co-founder of cell theory – 1st and 2nd statements 1838___
6. Rudolph Virchow ___Added third statement of cell theory 1855___
