Warm Up Create a word web with words you think of when you hear "Biology" Biology

Unit 2 - Reproduction -Cell Growth and Reproduction -Cell Division -Sexual and Aesexual Reproduction Zygotes and Development

During the 1800s scientists constructed what has come to be known as cell theory. This is where we will begin. The theory is based on 3 important principles: 1) All living things are composed of one or more cells. 2) The cell is the functional unit of life. 3) All cells come from pre-existing cells.

Scientific discovery oftens depends on technology available. Cell theory used technological advances in Microscopy to advance (aka THE MICROSCOPE) Microscopes provided scientists with a new view of cells. Greater magnification allowed them to discover smaller cells AND to gain a better understanding of how cells worked!

Magnification ObjectMagnification Fish Eggnone Human Egg10x Plant Cell20x Animal Cell50x Bacterium1000x Large Virus10 000x Ribosome40 000x Cell Membrane x Hydrogen Atom x Magnification needed to create a 1-mm image

What’s my power? T o calculate the power of magnification, multiply the power of the ocular lens by the power of the objective. What are the powers of magnification for each of the objectives we have on our microscopes? Fill in the table on your worksheet.

Body Tube Nosepiece Objectives Stage Clips Light Ocular lens (Eyepiece) Arm Stage Coarse Adjustment Fine Adjustment Always carry a microscope with one hand holding the arm and one hand under the base. Base Diaphragm Parts of a Microscope

aperture TOUCH THE SHAPE TO SEE IF YOU CAN NAME EACH PART CORRECTLY!

1. ____________________This disk under the stage controls the amount of light that passes through the aperture. 2. ____________________The mirror or lamp is located between these two things. 3. ____________________The flat place under the objective lenses where you place the slide for viewing. 4. ____________________This is the support for the entire microscope. 5. ____________________This part supports the entire upper portion of the microscope. DIAPHRAGM LEGS STAGE BASE ARM

6. ____________________This provides light so that so that it is easier to see the object you are viewing. 7. ____________________There may be 2 or 3 of these mounted to the nosepiece that magnify at different powers. 8. ____________________Light passes from the objective lens to the eyepiece through this part of the microscope. 9. ____________________These keep the slide from moving around the stage. 10. ___________________Where you look into the microscope. It also provides magnification. LAMP OR MIRROR OBJECTIVE LENSES BODY TUBE STAGE CLIPS EYEPIECE

1 1. ___________________Once the object that you would like to view comes into focus, you use this to fine-tune the image. 12. ___________________This is the thin piece of glass where you place your specimen. 13. ___________________You begin your focusing with this part of the microscope. 14. ___________________The opening in the stage that allows light through. 15. ___________________The objective lenses are mounted to this part of the microscope. FINE ADJUSTMENT KNOB SLIDE COURSE ADJUSTMENT KNOB APERTURE NOSEPIECE

Using a Microscope

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. 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.

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. 4 – When you are done, turn off the microscope and pick up the slides you used. 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!