Answers

1. What theory did these scientists provide evidence for?

*the cell theory

2. What instrument was necessary before the cell theory could be developed?

*The microscope

3. Which three scientists directly contributed evidence for the cell theory?

*Matthias Schleiden, Theodor Schwann, Rudolph Virchow

4. How did the earlier scientists and their contributions directly affect the discoveries of later scientists (see #2)? For example, what had to come first?

*Hans and Zacharias Janssen had to first develop the microscope before cells could be discovered. Robert Hooke then discovered empty, dead cork cells in tree bark. Anton van Leeuwenhoek discovered the existence of living cells and is sometimes given credit for the microscope.

5. List the three parts of the cell theory.

*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