1. 1. The Cell Theory UNIT THREE, LESSON 3.3 BY MARGIELENE D. JUDAN
2. 2. LESSON OUTLINE Cells and Scientists The Cell Theory The Modern Cell Theory The Modern Interpretation of the Cell Theory (Summary)
3. 3. The discovery of microscopes allowed the discovery of the tiny building blocks of life called cells. Robert Hookes microscope
4. 4. Robert Hooke first coined the term cell after he cut a piece of bark from an old oak tree in 1665.
5. 5. He called it cells because they are like hollow, rectangular rooms. Cork cells as seen by Hooke
6. 6. These cells are dead however. Cork cells as seen by Hooke
7. 7. In Filipino, the translation for the word cell is sihay. It such a wonderful term meaning silid ng buhay. Sihay silid ng buhay
8. 8. Aside from Hooke, many cytologists also contributed to develop the Cell Theory.
9. 9. 1. Anton van Leeuwenhoek Through his improved simple microscope, he was able to discover the tiny animals (bacteria, protozoan) which he called the animalcules. Animalcules sketched by Leeuwenhoek
10. 10. 2. Robert Brown Discovered the presence of nucleus within the cells nucleus
11. 11. 3. Felix Dujardin Said that cells contain a gelatinous fluid, a life substance called sarcode.
12. 12. 4. Johannes Purkinje Coined the term protoplasm which pertains to the living materials inside the cells
13. 13. 5. Rudolph Albert von Klliker Coined the term cytoplasm from protoplasm. Cytoplasm is a semisolid, semiliquid substance inside the cell that holds other cellular parts (except nucleus) Protoplasm includes nucleus, cytoplasm doesnt
14. 14. 6. Theodor Schwann Discovered that plants are composed of cells
15. 15. 7. Matthias Schleiden Discovered that animals are composed of cells
16. 16. 8. Rudolph Virchow Coined the statement omnis cellula e cellula, which means, cells divide and form new cells.
17. 17. All of them contributed, esp. the last three mentioned, to develop the cell theory. The cell theory is a scientific theory which describes the properties of cells.
18. 18. THE CELL THEORY 1. All living things are made of cells. 2. The cell is the basic unit of life. 3. Cells arise from pre-existing cells.
19. 19. 1. All living cells are made of cells. Cells may be prokaryotic (unicellular) or eukaryotic (multicellular). As mentioned earlier, Theodor Schwann said that plants are made up of cells, while Matthias Schleiden said that animals are also made up of cells.
20. 20. 2. The cell is the basic unit of life. Cells are composed of organelles which have specific functions to carry out life. (ex. chloroplasts manufacture chlorophyll)
21. 21. 3. Cells arise from pre-existing cells. Cells divide and form many cells. (reproduction)
22. 22. Modern studies led to the discovery of the key roles of cells. They are called the modern cell theory.
23. 23. THE MODERN CELL THEORY 1. The energy of organisms is formed in the cells. 2. Hereditary information (DNA) is passed on from cell to cell. 3. All cells have the basic chemical composition.
24. 24. 1. The energy of organisms is formed in the cell. The organelle called mitochondria* manufactures food to make energy in the form of ATP (adenosine triphosphate) molecule. (*We will study the function of each organelle in future lessons)
25. 25. 2. DNA is passed on from cell to cell. Prior to cell division, DNA is being replicated (copied) so that the offspring will have the DNA of its parent.
26. 26. 3. All cells have the basic chemical composition. Living cells are mainly made up of four elements: carbon, hydrogen, oxygen, and nitrogen. Without these molecules, life would not exist.
27. 27. To sum up, these are the general accepted parts of modern cell theory:
28. 28. THE MODERN INTERPRETATION 1. All known living things are made up of one or more cells. 2. All living cells arise from pre-existing cells by division. 3. The cell is the basic unit of life. 4. The activity of an organism depends on the activity of its cells.
29. 29. THE MODERN INTERPRETATION 5. The energy of organisms is formed in the cells. 6. Cells contain DNA (found in the chromosome) and RNA (found in the nucleus and cytoplasm). 7. All cells are basically the same in chemical composition in organisms of similar species.
30. 30. The last slide is a video about how DNA is replicated (copied). Notice carefully the complex and organized process and youll realize how God wonderfully made us according to His likeness.
31. 31. Performance Task: Divide the class into two groups. Each group will perform the Cell Song from Youtube (Keith Smolinski https://www.youtube.com/watch?v=KzMviiBoRtA) This will be our lesson after the Periodical Exam so you have more than one week to prepare. Its up to you how youll perform it. Put some creativity, props and actions to make it more entertaining. You can also change the tune of the song if you like. Just copy the lyrics later when you arrive home.
32. 32. Performance Task: The Cell Song by Dr. Keith Smolinski (2008) Lyrics (Chorus) Cells, cells , cells, cells The building blocks of life Cells, cells , cells, cells The building blocks of life Theyre in your pet and in your knees In your toes and all the trees Cells are in your families Cells, cells, cells. Most cells have a nucleus And it runs the show Its in the center of the cell And contains the genetic code The mitochondria Are the power plants of the cell Vacuoles store food and water Theyre useful just as well (Chorus)
33. 33. Performance Task: The Cell Song by Dr. Keith Smolinski (2008) Lyrics Ribosomes are working hard Making proteins one by one Golgi bodies pack them up Ship them off for fun The endoplasmic reticulum Carries protein carefully The lysosomes are janitors Clean the cell for free (Chorus) Cytoplasms the gel-like stuff That the cell parts are floating in The cell membrane says what goes out And what comes back in Plant cells have a thick cell wall To protect the parts within Chloroplasts make all the food When photosynthesis begins
34. 34. Performance Task: The Cell Song by Dr. Keith Smolinski (2008) Lyrics (Chorus) Coda Cells are in your families Cells, cells, cells. ***
35. 35. Assignment: Answer letter C, p. 121.
36. 36. Sources: Science Links 7 http://biology.about.com/od/biologydictionary/g/celltheor y.htm http://classroom.synonym.com/major-chemical-elements- found-cells-biology-21339.html https://en.wikipedia.org/wiki/Cell_theory