Do Now Copy down your homework in your agenda – EROSION PROJECT DUE MONDAY 11/18/13 Work with your group to label the parts of the microscope using the word bank on the group worksheet

Structure & Function of the Microscope On the next slide there is an image of a microscope, very similar to the scopes we use in class. Click on the boxes to see the name and function of each part of the microscope.

Objectives Identify the various parts of a microscope and define their purpose Calculate the power of magnification Use a diagram to distinguish between the powers of magnification

Parts of a microscope Contains the lens and magnifies the image for the viewer •

• Parts of a microscope A. Eyepiece Contains the OCULAR lens Contains the lens and magnifies the image for the viewer •

• Parts of a microscope B. Nosepiece Holds the HIGH- and LOW-power objective LENSES; can be rotated to change MAGNIFICATION Revolving circular structure containing the objectives •

• Parts of a microscope C. Objective Lenses Long= High Power C. Objective Lenses Magnification ranges from 10 X to 40 X Short = Low Power Lens that receives light from object to form a magnified image that you view through the eyepiece •

• Parts of a microscope D. Stage Clips HOLD the slide in place Used to hold the slide on the stage •

• Parts of a microscope E. Stage Supports the SLIDE being viewed Surface on which the slide is placed •

• Parts of a microscope F. Light Source Projects light UPWARDS through the diaphragm, the SPECIMEN and the LENSES Provides a steady stream of light that passes up through the bottom of the stage •

• Parts of a microscope G. Base Supports the MICROSCOPE

• Parts of a microscope H. Diaphragm Regulates the amount of LIGHT on the specimen Controls the amount of light that passes up through the bottom of the stage •

• Parts of a microscope I. Fine Adjustment Knob Moves the stage slightly to SHARPEN the image Used for focusing the microscope at different objectives •

• Parts of a microscope J. Coarse Adjustment Knob Moves the stage up and down for FOCUSING Used for focusing the microscope at different objectives •

• Parts of a microscope K. Arm Used to SUPPORT the microscope when carried Part of the microscope that is used for carrying •

Think Pair Share Why is it important to know and understand how to use all the parts of a microscope?

Rules of Handling and Using a Microscope Always carry with 2 hands Only use lens paper for cleaning Do not force knobs Always store covered Be careful with the cords

Magnification A microscope magnifies the object or slide on the stage using the eyepiece and objective To calculate the magnification multiply the eyepiece magnification (10X) by the objective magnification (4X, 10X, 40X)

What happens as the power of magnification increase? Example What happens as the power of magnification increase?

Comparing Powers of Magnification We can see better details with higher powers of magnification, but we cannot see as much of the image

Think Pair Share Slide 1 Slide 2 Which of these images is viewed at a higher power of magnification? Explain how you can tell.

How to Use a Microscope Place the slide on the stage Use stage clips to secure slide Adjust nosepiece to lowest setting (Lowest = shortest objective) Look into eyepiece Use coarse adjustment knob to focus the slide Use the fine adjustment knob to sharpen the focus

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.

You do not need to use the stage clips when viewing wet-mount slides! How to make a wet-mount slide … 1 – Get a clean slide and coverslip from your teacher. 2 – Place ONE drop of water in the middle of the slide. Don’t use too much or the water will run off the edge and make a mess! 3 – Place the edge of the cover slip on one side of the water drop. 4 - Slowly lower the cover slip on top of the drop. Cover Slip Lower slowly You do not need to use the stage clips when viewing wet-mount slides! 5 – Place the slide on the stage and view it first with the red-banded objective. Once you see the image, you can rotate the nosepiece to view the slide with the different objectives.