1. Discovery of the Cell and Cell Theory

2. Observations of Dead Cells Robert Hooke (1635- 1703) –First to view cells (dead cork cells) –Thought that the “little boxes” looked like the rooms where monks lived (cells)

3. Observations of Living Cells Anton van Leeuwenhoek (1632- 1723) –First to observe living cells

4. Observations of Living Cells cont. Matthias Schleiden (1804- 1881) –Concluded that all plants were made of cells

5. Observations of Living Cells cont. Theodor Schwann (1810-1882) –Concluded that all animals were made of cells

6. Observations of Living Cells cont. Rudolf Virchow (1821-1902) –Determined that cells only come from other cells

7. The Cell Theory (putting the observations together) 1.All living things are composed of one or more cells. 2.Cells are the basic units of structure and function in an organism. 3.Cells come only from the reproduction of existing cells.

8. What did Microscopes help scientists discover about all living things? Look back at your acrostic poem, your handout from yesterday, and your handout from last Monday. Otherwise use your textbook: Describe how Cell Theory was developed by what scientists had discovered thanks to microscopes

9. All Things are made of Cells! As microscopes got more complex, even small cells and single celled organisms could be studied. With this came the discovery of prokaryotes vs eukaryotes. Pro-before Karyote-kernel or nut Eu-true or good

10. Eukaryotic Vs Prokaryotic Prokaryotic Cell Eukaryotic Cell In your notes, write down what you see as the difference between the 2 cells.

11. All cells fall into one of two categories: prokaryotic or eukaryotic Prokaryotic cells evolved earlier in history than eukaryotic cells Prokaryotic cells lack several of the features found in eukaryotic cells You are eukaryotic. –Your cells have a nucleus and membrane-bound organelles.

12. Prokaryotes Eukaryotes

13. Prokaryotic vs. Eukaryotic cont. Prokaryotic CellEukaryotic Cell Cell Membrane May be unicellular May be multicellular Has membrane- bound organelles Has a membrane- bound nucleus Contains DNA or other genetic info

14. How are Prokaryotes and Eukaryotes Different? Look over your notes and describe the differences between a prokaryote and eukaryote. How does knowing the root of the word help you to describe this difference?

15. Intro to Cell Structure Quick Review: –Cells = basic unit of life –Unicellular: the organism is just one cell –Multicellular: the organism has lots of cells, each carries out a specific job All cells have: –Cell membrane –Cytoplasm (with organelles) –DNA (genetic material)

16. Cell membrane Thin barrier separating the cytoplasm and contents of the cell from the external environment. In some cells the membrane is surrounded by a cell wall. –The cell wall is a thick, rigid structure surrounding plant and bacteria cells.

17. Inside a Cell Cytoplasm –space inside the cell, between the membrane and nucleus that contains a semi-liquid substance and houses the organelles. Nucleus –spherical organelle that contains the DNA of eukaryotic cells. Visible in most cells under a light microscope All plant and animal cells are eukaryotic. Organelles = –specialized structures that carry out cell functions Most are not visible using only a light microscope

18. Finish your Microscope poster for tomorrow Come ready to take a test. Bring your Green Lab Manual, and read over Lab 6.

19. Onion Cells

20. Elodea Cells

21. Cheek Cells