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1. What is cell theory?

2. Are there living organisms without cells?

3. In 1665, Robert Hooke, an English scientist, published his book Micrographia, in which he described that pieces of cork viewed under a microscope presented small cavities, similar to pores and filled with air. Based on knowledge discovered later on, what do you think those cavities were composed of? What is the historical importance of this observation?

4. What are the two main groups into which cells are classified?\

5. Do the cells of bacteria have a nucleus?

6. Are any bacteria made of more than one cell?

7. What is the plasma membrane of the cell? What are its main functions?

8. What chemical substances compose the plasma membrane?

9. What is the difference between a plasma membrane and a cell wall?

10. What are the main respective components of cell walls in bacteria, protists, fungi and plants?