Do Now(1) How many: Cm in 4 meters? Decimeters in 5 meters? Cm in 4000 mm? Millimeters in 40 cm? How do we measure volume? Give good review… draw the steps

About how big is that? Length of a big step, baseball bat Width of your finger or fingernail Thickness of fingernail or dime 1 meter 1 centimeter 1 millimeter

Microscope: Identify parts & function Have students try and match up the parts of the microscope with their function. Then go over the parts and their functions. Spend a lot of time demonstrating how to hold and use the microscope. Students did not have much pre-knowledge… some basic parts they got were “the arm” “stage clips” Had to review only a few minutes into the demonstration

Rapid Fire Scenarios An image is too dark while viewing. What should you do? An image is too blurry or not clear. What should you do? The image is small and you want to zoom it to see it closer. What do you do? You are trying to get the slide to stay in place on the stage. What do you do? You go to pick-up the microscope. How do you do it?

Rapid Fire Scenarios You are looking under LOW power and want to use the adjustment knobs. What do you use? You are looking under HIGH power and want to use the adjustment knobs. What do you use? Why? NEVER USE coarse adjustment under high power!! You may crack the very expensive microscope or break the glass viewing slide!

Compound Microscope Purpose – to view tiny living and non-living specimens not visible or clear to the naked eye. Mainly used to view cells. To view smaller objects, the microscope magnifies images using 2 lenses at a time Total magnification - the ocular lens (eyepiece) and the objective lens combine to magnify an image End here LP 5.1

Do Now Use these words and create a sentence: Coarse adjustment, stage, low power Only, high power, fine adjustment, focus

Magnification What is magnification? 10x magnification means the lens makes the object appear 10x larger

Magnification When you magnify an image more, do you see more or less of an image? You see less! Your field of view DECREASES as you increase magnification Use the meter stick!! Field of view – the total area you see

DO NOW Page 8 & 9 # 6, 12, 16 Begin here LP 5.2

Lenses and total Magnification Looking through the microscope you are viewing an object through how many lenses? There is always 1 ocular lens on a microscope (can’t change) BUT, microscopes have usually 2 or 3 objective lenses Low power objective (for us… either 4x or 10x magnification) High power objective (for us… 40x, depending on microscope) 2… (Ocular & Objective)

Lenses and total Magnification Total magnification – the total amount an image is magnified To calculate total magnification Since when you look through a microscope you look through two lenses… Simply multiply the ocular lens (eyepiece) by the objective lens Magnifications will be shown on the lenses Eyepiece magnification x Objective magnification = Total Magnification

Calculating Total Magnification Eyepiece Power Objective Power Total Magnification 10x 40x 200x 1000x

Calculating Total Magnification Practice Problem: Calculate the low-power and the high-power total magnifications of a microscope with an eyepiece magnification of 10x, a low-power objective of 20x, and a high-power objective of 40x. Low power total magnification = High power total magnification =

Lets check this stuff out http://virtualurchin.stanford.edu/microscope.htm Focus – Low mag – High mag End here LP 5.2

Do Now Write on page 12: Use these words and create a sentence: Coarse adjustment, stage, low power Only, high power, fine adjustment, focus Begin LP 5.3 here periods 1,7

Do Now Write on page 12: List 5 ways that a microscope and it’s parts are correctly used… Begin LP 5.3 here period 6

Microscope Viewing When focusing on a specimen: Place your slide on the stage and secure it under the stage clips Use the low power objective and use the coarse adjustment to focus and find the image Once in focus, CENTER the image Why? Finally, switch to the higher power objectives and ONLY use the FINE ADJUSTMENT to focus! So you can still see the image when you increase magnification because your field of view gets smaller! BEGIN here for LP 5.3

DO NOW

What do you see under the microscope? Images appear: Upside down AND backwards Have students draw an “F” and a “J” as they would appear under the microscope

What happens if we move the specimen? If you move an image to the right, when you look through the microscope, it will appear to be moving left! Remember…. everything is BACKWARDS!

How do we make the slides that we are going to look at anyway? Preparing a slide to view is called – creating a wet-mount.

Creating a Wet Mount Obtain a clean microscope slide and hold by edges. Using forceps, take your specimen and place on slide Use a dropper to put one drop of water onto the specimen Take cover slip, hold at a 45⁰ ANGLE to the slide and lower it SLOWLY until the specimen is covered. WHY? To prevents BUBBLEs from getting trapped DEMONSTRATE this… if you can’t find a video (you tube) END LP 5.3 here

Sometimes Dye is added to a wet mount Why? Using a dropper, add dye to the edge of the coverslip that is covering your specimen. Place a small piece of a paper towel on the opposite side of the cover slip The added dye or liquid will travel under the cover slip because the water on the opposite side is being absorbed by the towel! To make a specimen more visible End here LP 5.3

Measuring objects under a microscope Measurement used = How big is a micrometer (micron)? There are 1,000 micrometers in 1 millimeter! Where does this fit on our staircase of conversions? Micrometer (um)

Convert me mm um 1 mm 6 mm 1,200 um 2.5 mm 4,000 um

Looking at a metric ruler under a microscope The smallest lines you can see that are drawn on a metric ruler are… You now know there are 1,000 um in 1mm… tell me how big my field of view is (diameter) in the picture. Millimeters (mm) What is your field of view in:   Mm: ________ Um: ________

Regents Question

What is your field of view? Picture B, what is your field of view in: Mm: ________   Um: ________

Measuring objects under a microscope

B

C

DO NOW (page 12) Describe the steps on how to properly use a microscope. Know your groups: (I will tell you and THEY ARE FINAL) Introduction to LAB on microscope