1. Slide 1 of 31 Copyright Pearson Prentice Hall 7-1 Life Is Cellular

2. Slide 2 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell The existence of cells was unknown for most of human history. WHY? No one could see them! This changed with the invention of the microscope.

3. 7-1 Life Is Cellular Slide 3 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell Early Microscopes In 1665, Robert Hooke used an early compound microscope to look at a thin slice of cork, a plant material. Cork looked like thousands of tiny, empty chambers. Hooke called these chambers “cells.” Cells are the basic units of life.

4. 7-1 Life Is Cellular Slide 4 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell Hooke’s Drawing of Cork Cells

5. 7-1 Life Is Cellular Slide 5 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell At the same time, Anton van Leeuwenhoek used a single-lens microscope to observe pond water and other things. The microscope revealed a world of tiny living organisms.

6. 7-1 Life Is Cellular Slide 6 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell What is the cell theory?

7. 7-1 Life Is Cellular Slide 7 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell The Cell Theory – Important Scientists In 1838, Matthias Schleiden concluded that all plants were made of cells. In 1839, Theodor Schwann stated that all animals were made of cells. In 1855, Rudolph Virchow concluded that new cells were created only from the reproduction of existing cells. These discoveries led to the cell theory.

8. 7-1 Life Is Cellular Slide 8 of 31 Copyright Pearson Prentice Hall The Discovery of the Cell The cell theory states: 1. All living things are composed of cells. 2. Cells are the basic units of structure and function in living things. 3. New cells are produced from existing cells.

9. 7-1 Life Is Cellular Slide 9 of 31 Copyright Pearson Prentice Hall Exploring the Cell New technologies allow researchers to study the structure and movement of living cells in great detail. The microscope is one of the greatest inventions in the advancement of cell biology today.

10. 7-1 Life Is Cellular Slide 10 of 31 Copyright Pearson Prentice Hall Microscopes The van Leeuwenhoek microscope

11. 7-1 Life Is Cellular Slide 11 of 31 Copyright Pearson Prentice Hall Microscopes This is an original van Leeuwenhoek microscope preserved in his home town of Delft. It is about the size of a postage stamp.

12. 7-1 Life Is Cellular Slide 12 of 31 Copyright Pearson Prentice Hall Microscopes Microscopes through the years: 1875 1828 1680 1725 1750

13. 7-1 Life Is Cellular Slide 13 of 31 Copyright Pearson Prentice Hall Microscopes Electron Microscopes Electron microscopes reveal details 1000 times smaller than those visible in light microscopes. Electron microscopy can be used to visualize only nonliving, preserved cells and tissues. Antarctic mite

14. 7-1 Life Is Cellular Slide 14 of 31 Copyright Pearson Prentice Hall Microscopes Modern Compound Light Microscope

15. 7-1 Life Is Cellular Slide 15 of 31 Copyright Pearson Prentice Hall Microscopes

16. 7-1 Life Is Cellular Slide 16 of 31 Copyright Pearson Prentice Hall Eyepiece Body Tube Arm Stage Clips Coarse Adjustment Fine Adjustment Stage Switch Revolving Nosepiece High Power Objective Low Power Objective Diaphragm Light Source Base Microscopes

17. 7-1 Life Is Cellular Slide 17 of 31 Copyright Pearson Prentice Hall Microscopes 1. 3. 4. 6 7. 5. 8. 9. 10. 11. 12. 13. 14. 2.2.

18. 7-1 Life Is Cellular Slide 18 of 31 Copyright Pearson Prentice Hall Microscopes Carrying Your Microscope Correctly

19. 7-1 Life Is Cellular Slide 19 of 31 Copyright Pearson Prentice Hall Microscope Incorrectly Carrying Your Microscope

20. 7-1 Life Is Cellular Slide 20 of 31 Copyright Pearson Prentice Hall Microscopes Putting Your Microscope Away Storing your scope for use the next time requires that you follow a few easy steps – REMOVE THE SLIDE FROM THE STAGE -Dispose of the specimen as directed by your teacher. -Clean the slide and cover slip -Return the slide and cover slip to its proper place.

21. 7-1 Life Is Cellular Slide 21 of 31 Copyright Pearson Prentice Hall Microscopes Always Store Your Scope on 10X.

22. 7-1 Life Is Cellular Slide 22 of 31 Copyright Pearson Prentice Hall Microscopes Unplug Your Scope Correctly.

23. 7-1 Life Is Cellular Slide 23 of 31 Copyright Pearson Prentice Hall Microscope Wind the Cord Around the Base.

24. 7-1 Life Is Cellular Slide 24 of 31 Copyright Pearson Prentice Hall Microscope Cover Your Scope Before Returning It.

25. 7-1 Life Is Cellular Slide 25 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes Types of Cells Cells come in a variety of shapes and sizes. All cells: are surrounded by a barrier called a cell membrane. at some point contain DNA.

26. 7-1 Life Is Cellular Slide 26 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes Cells are classified into two categories based upon whether or not they contain a nucleus. Eukaryotes are cells that contain a nucleus. Prokaryotes are cells that do not contain a nucleus. The nucleus is the structure that contains the cell's DNA and controls many of the cell's activities.

27. 7-1 Life Is Cellular Slide 27 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes What are the characteristics of prokaryotes and eukaryotes?

28. 7-1 Life Is Cellular Slide 28 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes Prokaryotes Prokaryotic cells have genetic material that is not contained in a nucleus. Prokaryotes do not have membrane-bound organelles. Prokaryotic cells are generally smaller and simpler than eukaryotic cells. Bacteria are prokaryotes.

29. 7-1 Life Is Cellular Slide 29 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes

30. 7-1 Life Is Cellular Slide 30 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes Eukaryotes Eukaryotic cells contain a nucleus in which their genetic material is separated from the rest of the cell.

31. 7-1 Life Is Cellular Slide 31 of 31 Copyright Pearson Prentice Hall Prokaryotes and Eukaryotes Eukaryotic cells are generally larger and more complex than prokaryotic cells. Eukaryotic cells generally contain dozens of structures and internal membranes. Many eukaryotic cells are highly specialized. Plants, animals, fungi, and protists are eukaryotes.

32. - or - Continue to: Click to Launch: Slide 32 of 31 Copyright Pearson Prentice Hall 7-1

33. Slide 33 of 31 Copyright Pearson Prentice Hall 7-1 The cell theory states that new cells are produced from a.nonliving material. b.existing cells. c.cytoplasm. d.animals.

34. Slide 34 of 31 Copyright Pearson Prentice Hall 7-1 The person who first used the term cell was a.Matthias Schleiden. b.Lynn Margulis. c.Anton van Leeuwenhoek. d.Robert Hooke.

35. Slide 35 of 31 Copyright Pearson Prentice Hall 7-1 Electron microscopes are capable of revealing more details than light microscopes because a.electron microscopes can be used with live organisms. b.light microscopes cannot be used to examine thin tissues. c.the wavelengths of electrons are longer than those of light. d.the wavelengths of electrons are shorter than those of light.

36. Slide 36 of 31 Copyright Pearson Prentice Hall 7-1 Which organism listed is a prokaryote? a.protist b.bacterium c.fungus d.plant

37. Slide 37 of 31 Copyright Pearson Prentice Hall 7-1 One way prokaryotes differ from eukaryotes is that they a.contain DNA, which carries biological information. b.have a surrounding barrier called a cell membrane. c.do not have a membrane separating DNA from the rest of the cell. d.are usually larger and more complex.

38. END OF SECTION