Introduction to the Microscope Lab Activity



Introduction to the Microscope: Lab ActivityMicroscopes are tools used to enlarge images of small objects so as they can be studied. The compound light microscope is an instrument containing two magnifying lenses and a variety of knobs to resolve (focus) the picture.- Magnification: ability to enlarge an image- Resolution: ability to produce a clear image- Field of View: the circle of light that you see when you look into the microscope. As magnification increases, the field of view decreases.I. Know your microscope. 1. Examine the microscope and label the parts in the diagram.2. Indicate the function of each of the parts in the table below.1600200175895Microscope LabelingJPartFunctionA.B.C.D.E.F.G.H.I.J.II. How to determine Total Magnification102870033655Complete the table below for the 3 objectivesEyepiece magnification ______________(X)Objective magnification ______________=Total Magnification _____________XEyepiece magnification ______________(X)Objective magnification ______________=Total Magnification _____________XEyepiece magnification ______________(X)Objective magnification ______________=Total Magnification _____________XIII. Preparing a wet mount of the letter eWith your scissors cut out the letter "e" from the newspaper. 20574004445Place one or two drops of water in the center of the slide.Place the letter e in the drop of waterPlace a coverslip on top as shown in diagram C and D. This procedure prevents the formation of air bubbles.IV. Observing the letter eTurn on the microscope and place the slide on the stage. Use the clips to secure it.Using the low power objective, turn the coarse focus until the letter e can be seen.Use the fine focus to focus clearly.Draw what you see.How is the letter e positioned?_______________________________________________________________________________________E. Looking through the eye piece, move the slide to the right. What direction does the letter move? ___________________________________F. Looking through the eye piece, move the slide up, away from you. What direction does the letter move? ___________________________________G. Re-center the slide and change the objective to medium power. DO NOT TOUCH THE COARSE FOCUS. Use the FINE FOCUS to focus.H. Draw what you see.I. Do you see more or less of the letter e under medium power?________________________________________________________________________________________Locate the diaphragm under the stage. Move it around.What do you notice?________________________________________________________________________________________V. Depth of Field: Thread wet mount A. Prepare a wet mount of a red and white thread. Make sure that the 2 threads cross each other as shown here. B. Locate the threads under low power.Can you see all the strands clearly at the same time? ____________________________C. Change to medium power and observe the threads at the point where they cross.D. Draw what you see.Can you see all the strands clearly, at the same time? ______________________________________Which color thread is in focus?______________________________________E. Change to high power and observe the strands at the point where they cross.Can you see all the strands clearly at the same time? ___________________________Which color thread is in focus? ____________________________________________F. To see the strands at different depths you need to turn the fine focus while looking through the microscope. Try it!Microscope Scavenger HuntCork: Take a look at what Robert Hooke looked at in the 1600s!-Use low magnification.-Switch to medium power and then high power.-Draw the “cells” as Hooke did.What are you really seeing?Hydra. This is a relative of sea anemones found in freshwater. It attaches to rocks, and other substrates. - How many tentacles do you see? ______How many cells do you think Hydra has? __________- Draw the hydra at low power and label the tentacles.Paramecium. This is a unicellular organism. Just one cell! They live in water. - Using low power find a few Paramecium (purple). - Switch to medium power. - Draw 2 Paramecium. Pollen grains: This is what pollen looks like.- Use low magnification. - How many different types of pollen do you see? ________- Change to medium power. - Draw 3 different pollen grains.Frog Blood. Yes, frog blood.- Using low power, look at the purple dots. - Switch to medium power and focus. - Switch to high power. - What is the darker spot in the middle? ______________- Draw one red and one white blood cell. Adipose tissue. These are cell that specialize in storing fat.- Using low power look at the area with white spots. - Switch to medium power and focus. - Switch to high power. - Draw about 5 cells.- Where is the nucleus? ____ ................
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