Transcript File
Do Now #1 #4 #3 #2 #5 1 Microscopes Microscopes • Microscopes are devices that produce magnified images of things that are too small to see with the unaided eye means “small” in Greek, and skopmeans “see.” – Micro- Types of Microscopes • Light microscopes produce magnified images by focusing visible light rays. • Electron microscopes produce magnified images by focusing beams of electrons. Properties of Microscopes • When we examine microscopes, we focus on two properties: – 1) Magnification—how much larger can it make an object appear compared to its actual size – 2) Sharpness—the clearness and crispness of the image Light microscopes • Light microscopes are the most commonly used microscopes. • Light microscopes can produce clear images of objects at a magnification of 1000x. • Compound light microscopes allow light to pass through the specimen and use two lenses to form an image. Electron Microscopes • Electron microscopes can be used to view objects that are 1000x smaller than those visible under a light microscope • Because these microscopes don’t use light, the images produced have no color • Additionally, electron microscopes cannot be used to examine living things Body Tube Ocular lens (Eyepiece) Nosepiece Objectives Arm Stage Stage Clips Coarse Adjustment Diaphragm Light Fine Adjustment WHAT’S MY POWER? • To calculate the power of magnification, multiply the power of the ocular lens (in the eyepiece) by the power of the objective lens Comparing Powers of Magnification • We can see better details with higher the powers of magnification, but we cannot see as much of the image. • Which of these two images is viewed at the higher power of magnification? Let’s give it a try ... 1 – Turn on the microscope and then rotate the nosepiece to click the red-banded objective into place. 2 – Place a slide on the stage and secure it using the stage clips. Use the coarse adjustment knob (large knob) to get it the image into view and then use the fine adjustment knob (small knob) to make it clearer. 3 – Once you have the image in view, rotate the nosepiece to view it under different powers. Draw what you see on your worksheet! Be careful with the largest objective! Sometimes there is not enough room and you will not be able to use it! 4 – When you are done, turn off the microscope and put up the slides you used.