Cells and Living Things

1. Cells and Living Things

2. Read pp. 388-396

3. Cell • Smallest basic functional unit of life • All living things are made up of one or more cells

4. Four characteristics common to living things • All living things grow • Cell number increases and new cells replace old cells • All living things move • Movement involves changes to shape and position or can refer to legs and wings! • All living things respond to stimuli in their environment • A stimulus is anything that causes a living thing to respond • A cat hisses; your stomach rumbles • All living things reproduce • Produce more of their own kind (offspring)

5. Examining very small living things • Anything smaller than 0.1mm the naked eye can’t see, so you need a microscope • The microscope is used by scientists to observe very small unicellular and multicellular living things. • Early microscopes were built in the late 1600’s. • Anton van Leeuwenhoek was oneof the first people to build amicroscope. • He could magnify up to 250x, andused it to observe microscopicliving things.

6. Compound Microscope • The compound light microscope hastwo sets of lenses that magnify an image. • When you look through a microscope you see a magnified, inverted and reversed image. • Each of the objective lenses has adifferent magnification power. • Low power = 4x objective • Med power = 10x objective • High power = 40x objective • Multiply the objective by theeyepiece for total magnification. • Example: High Power = 40 x 10 = 400 x

7. Microscope foldable • Distribute a microscope image • Add flaps to each part with the definition of each beneath the flap.

8. Microscope resolving power • The ability to distinguish between two dots or objects that are very close together is called resolving power. • The human eye has a certain resolving power. You can see the individual dots in diagrams A, B and C. The human eye does not have the resolving power to see the dots in diagram D.

9. P. 397 • Questions 1-4

10. CORE LAB – Setting up and using a microscope

11. Check your understanding • Questions 1, 2, 3, 4, 5, 6, 7, and 9 • Pause and reflect

12. Read pp. 402-406

13. Cell parts • An analogy is a way to understand new ideas by making a comparison. • A factory can be used as an analogy for the cell. • Parts of the cell that allow the cell to survive are called organelles. • Organelles take up about 5 to 30 percent of the cell. The rest of the cell consists of water. • Read pp. 402-403 • Do activity 10-2A, p. 404 (perhaps a class discussion)

14. The Functions of Cell Organelles • The cell membrane protects the cell and selectively regulates the movement of particles in and out of the cell. • Cytoplasm, the jelly-like substance within the cell, contains organelles, water, and other life supporting materials. • The nucleus: • controls all the activities within the cell. • contains deoxyribonucleic acid (DNA).

15. Energy in the Cell • The mitochondria are the organelles that produce energy in the cell. • When the cell changes chemical energy, in the food we eat, to energy the cell can use, it is called cellular respiration. • The total of all the chemical reactions that take place in our cells is called our metabolism. (c) McGraw Hill Ryerson 2007 Cellular Respiration

16. Organelles for Assembly, Transport, and Storage • Proteins are essential for all life and are assembled by the ribosomes. • Proteins then pass through the endoplasmic reticulum and are placed in vesicles by the Golgi body. • Vacuoles are temporary storage compartments. • Lysosomes break down food particles, cell wastes, and worn-out organelles. (c) McGraw Hill Ryerson 2007 See pages 28-29

17. The Difference Between Plant and Animal Cells • Plant cells have two parts that are not found in animal cells: • Cell Wall • protects the cell and gives cell shape • Chloroplasts • change the Sun’s energy into chemical energy • Other key difference is plants have on large vacuole whereas animal cells have several small vacuoles. (c) McGraw Hill Ryerson 2007 Locate the cell wall and chloroplast See pages 29-30 Photosynthesis

18. QUIZ!!!!

19. Cell Theory • The cell is the basic unit of life. • All organisms are composed of one or more cells. • All cells come from other living cells. (c) McGraw Hill Ryerson 2007

20. Plant and animal organelles • Organelle ~ structures of cells that perform a specific function • Create a foldable of an animal and a plant cell • Draw a typical plant cell on a large sheet of paper. • Create flaps for each organelle with the definition of each underneath

21. CREATE A 3D model of a cell (class activity) p. 407

22. LAB 10-2C Plant vs. Animal cells

23. Dividing cells • Read p. 410-411 • All cells divide during their life cycle • When cells divide, one cell becomes 2! • Your skin cells divide to replace the cells you rub off or if you scrape yourself. • When a cell divides, the genetic material duplicates and then divides into 2 identical sets of chromosomes – this is called mitosis. • Each daughter cell (the new cells) gets one set of the duplicated genetic material. • See figure 10.10 • Only exception to this type of division is your sperm cell and egg cells (more on this next year)

24. Checking concepts... • Questions 1-16 • Test