2. Cell Structure Chapter 3 Looking at Cells Section 1

3. Levels of Organization: Level 1 Atom Explanation/Description : Smallest unit of matter that cannot be broken down. Examples : Hydrogen atom, Oxygen atom

4. Levels of Organization: Level 2 Molecules Explanation/Description : Groups of atoms; smallest unit of most chemical compounds Examples : Water, DNA

5. Levels of Organization: Level 3 Organelle Explanation/Description : specialized part of a cell Examples : Chloroplasts, Mitochondria

6. Levels of Organization: Level 4 Cells Explanation/Description : Smallest functional unit of life Examples : Nerve Cell

7. Levels of Organization: Level 5 Tissues Explanation/Description : Made up of cells that are similar and work together to perform a specific activity Examples: Nervous Tissue

8. Levels of Organization: Level 6 Organs Explanation/Description: Made up of tissues that work together to perform a specific activity Examples: Brain, Heart

9. Levels of Organization: Level 7 Organ Systems Explanation/Descrip tion : Groups of two or more tissues that work together to perform a specific function for the organism. Examples : Nervous System, Urinary System

10. Levels of Organization: Level 8 Organism Explanation/Description : Individual Living Thing Examples : Bison

11. Levels of Organization: Level 9 Population Explanation/Description : group of organisms of one type that live in the same area Examples: Bison Herd

12. Levels of Organization: Level 10 Community Explanation/Description: Populations that live together in a defined area Examples : Hawk, snake, bison, prairie dog, grass

13. Levels of Organization: Level 11 Ecosystem Explanation/Description : Community and its nonliving surroundings Examples: Hawk, Snake, bison, prairie dog, grass stream, rocks air

14. Levels of Organization: Level 12 Biosphere Explanation/Description : the part of the earth that contains all ecosystems Examples : Whole world, everything living and nonliving thing.

15. Section 1: Looking at Cells Microscopes and More 14

16. Invention of the Microscope Robert Hooke—used a crude microscope to observe cork in 1665. Saw tiny boxes- called them cells

17. Invention of the Microscope Anton van Leeuwenhoek– used a microscope to observe pond water in 1675. “Animalcules”- tiny animals

18. Characteristics of Microscopes Magnification– making an image appear larger than it is. 20x indicates that object appears 20 times larger than it is..

19. Characteristics of Microscopes Resolution— how clear the image is. Which is clearer? One of the right or left?

20. Two common kinds of microscopes 1. Light Microscope 1. Light passes through lenses to produce an enlarged picture of a specimen. Compound Light Microscope- uses two lenses (ocular and objective) Both lenses magnify the object Ex. Ocular: 10x Objective: 40x Total Magnification 400x Most powerful light microscope: 2000x

21. Always carry with 2 hands Only use lens paper for cleaning Do not force knobs Always store covered Keep objects clear of desk and cords

22. Eyepiece: contains the ocular lens (10x) Body Tube Revolving Nosepiece: holds the objective lens can be rotated to change magnification Arm: used to support the microscope when carried Objective Lens: magnification ranges from 5X-40X Stage: supports the slide being viewed Stage Clips: hold the slide in place Coarse Focus: moves the stage up and down for focusing Fine Focus: moves the stage slightly to sharpen the image Base: supports the microscope Diaphragm: regulates the amount of light on the specimen Light Projects light upward through the specimen and lenses

23. Place the Slide on the Microscope Use Stage Clips Click Nosepiece to the lowest (shortest) setting Look into the Eyepiece Use the Coarse Focus

24. Follow steps to focus using low power Click the nosepiece to the longest objective Do NOT use the Coarse Focusing Knob Use the Fine Focus Knob to bring the slide into focus

25. Hyaline Cartilage

26. Skeletal Muscle Cells

27. Blood Cells

28. Single Cell Algae

29. Diatoms

30. Sperm

31. Two common kinds of microscope 2. Electron Microscope - Uses beams of electrons to form a enlarged picture of the specimen - Two kinds of electron microscopes - Scanning - Transmission Most powerful is 200,000x

32. Scanning Electron Microscope - Electron beam focuses on a specimen covered with thin layer of metal. - Electrons bounce off the specimen and form a image on a fluorescent screen - 3D black and white images

33. Scanning Electron Microscope

34. Pollen Grain

35. Tarantula

36. Neurons

37. Heart Fibers

38. Transmission Electron Microscope - Electron beam is directed at a thin slice of specimen covered in metal ions - Electrons are absorbed in heavily stained areas - Electrons go through areas that are not heavily stained and hit a fluorescent screen.

39. Transmission Electron Microscope

40. Virus

41. Bacteria

42. Ebola Virus

43. Honey Bee