1. MICROSCOPE An instrument that magnifies, by many times, images of objects that are too small to see with the naked eye.

2. TYPES OF MICROSCOPES Optical (light) microscopes Electron microscopes

3. VOCABULARY WORDS Magnification: the number of times an object is enlarged A magnification of « 100x » means that the image is 100 times larger than the actual object Resolution: the ability of the microscope to produce a clear and precise image; the ability to separate the details

4. Optical (light) microscope Made up of several lenses that « bend » light to enlarge the image of a specimen Needs a light source Resolution: objects that are as small as 200nm (the size of a bacteria) A magnification of 40X to 1000X Can be used to view live specimens

5. Electron microscope …transmission (TEM): electrons go through the object …scanning (SEM): electrons « sweep » across the surface of an object Images are projected on a screen Magnifications up to 2 000 000X!

6. Electron Microscopes Transmission Electron Microscope (TEM): Used to study the internal structure of cells (eg. organelles) Scanning Electron Microscope (SEM): Used to study the surface of a specimen. Produces a 3-D image The specimen has to be dead

7. Electron Microscope Images

17. THE VIRUS THAT CAUSES AVIAN FLU Transmission Electron Microscope (TEM) Scanning Electron Microscope (SEM)

18. Dust mites (found in dust)

19. The compound light microscope A. B. C. D. E. F. G. H. I. J. K. L.

20. Rules to using the microscope 1.Always carry the microscope with two hands : one on the arm, the other underneath the base. 2.Clean the microscope before use using lens paper or tissue paper only. 3.Start with the lowest power objective (4x – the shortest objective) and adjust the focus with the Coarse Adjustment Knob. a.If you change objective lenses to a higher power lens but cannot find the specimen or cannot focus, return to the lowest objective lens and try again. 4.Never use the Coarse Adjustment Knob when the highest power objective (40x) is in position over a specimen. ONLY use the Fine Adjustment Knob to focus. 5.Adjust the diaphragm to have the appropriate quantity of light. a.This will help when using higher power objective lenses. 6.Putting the microscope away: a.Return the lowest power objective to the position over the stage. b.Turn the Coarse Adjustment Knob until the stage reaches its lowest position. c.Remove the slide from the stage. d.After giving the lamp time to cool, roll the cord around the lamp. e.Return the microscope.

21. CALCULATIONS Magnification = (power of the ocular lens) x (power of the objective lens) *the power of the ocular lens is usually 10X Calculating the magnification for the objective lenses: Low power 4X 10X x 4X = 40X Medium power 10X 10X x 10X = 100X High power 40X 10X x 40X = 400X

22. SCIENTIFIC DRAWINGS Title of observation: animal cell Magnification of ocular lens: 10x Magnification of objective lens: 40x Total magnification: 400x *Use a ruler for ALL labels *Identify ALL possible internal structures *Draw as realistically and neatly as possible Cell membrane Nucleus Cytoplasm