GREEN RIVER COMMUNITY COLLEGE IDS Unit 1 DPM © IDS Microscope Lab 1 Worksheet (page 1) MICROSCOPE LAB 1 Worksheet Team Names ___________________ ____________________ 1. Using low power compare the position and orientation of the image of the letter e seen through the ocular with the position of the printed e (the object) on the slide as seen with your eye. What two orientation differences of the image are there? 2. Slowly move the slide horizontally away from you. ________________________ Which way does the image move? (place answer here) 3. While looking into the ocular, slowly move the slide from right to left. Which way does the image move? ________________________ (place answer here) 4. Approximately how much of the letter e is visible when viewing it under high power? (Give a percent based on ______ the differences in the size of the field of views.) (place answer here) 5. Does the switch from low power to high power ___________ change the position of the image? (place answer here) 6. Why is it necessary to center your object (or the position of the slide you wish to view) before changing to high power? 7. Under high power is the illumination brighter or less bright _______ than it is with low power? (place answer here) 8. Move the iris diaphragm lever while observing the field. What happens? 9. Is it more desirable to increase or decrease the light when changing to a higher magnification? (place answer here) 10. What is the approximate actual height - in millimeters and microns (µm) - of your letter e? (place answer here)GREEN RIVER COMMUNITY COLLEGE IDS Unit 1 DPM © IDS Microscope Lab 1 Worksheet (page 2) 11. Fill in the Summary Chart given below Scanning Low Power High Power Oil Immersion Magnification of Objective Lens X X X X Total Magnification X X X X Field Size (diameter) mm mm mm mm Field Size (diameter) µm µm µm µm Use the data for the following four microscopes to answer questions 12 - 13 Microscope Number Objective Lens Ocular Lens 1 2 3 4 25X 15X 20X 40X 5X 10X 10X 5X 12. If a slide showing the same types of living organisms is examined with each of the microscopes, in which two microscopes will _______ the microbes appear to move with the same degree of rapidity? (Place answer here) 13. Given that each slide had the same density of microbes, with which microscope would you expect to observe the ______ greatest number of microbes at any given instant? (Place answer here) 14. What is meant by resolution (resolving power) of a microscope? 15. A hypothetical microscope you are using has the following objective magnifications: scanning objective 3X, low power objective 12X and high power objective 30X. If the diameter of the scanning objective field is 6000 microns (micrometers), what is the diameter of the low power field of view in microns?GREEN RIVER COMMUNITY COLLEGE IDS Unit 1 DPM © IDS Microscope Lab 1 Worksheet (page 3) 16. You observe an object whose length is 1/4 the diameter of the high power field of view of the hypothetical microscope in #15 above. What is its length in microns? 17. Calculate the length of the following microscopic objects. Base your calculations on the field sizes you have determined for the microscope you actually used today. (See chart page 2.) a. Object seen in low-power field: A Calculated length: _________mm b. Object seen in high-power field: B Calculated length: _________mm c. Object seen in oil immersion field: C Calculated length: _________mm 18. If a slide were set up with a layer of Green, Blue, and Red threads as diagrammed, which layer would come into focus first if you positioned the stage as close to the low power objective lens as possible and then brought the slide into focus? (Note: Colors do not mix.) A. Blue first. B. Red first. C. Green first. D. all three colors at once. 19. In the space below sketch an unstained and a stained starch grain. Identify which is which. 20. In the space below, sketch on the left a starch grain receiving a high concentration of stain and sketch on the right a starch grain receiving a low concentration of I2KI. B C A Slide Green Blue RedGREEN RIVER COMMUNITY COLLEGE IDS Unit 1 DPM © IDS Microscope Lab 1 Worksheet (page 4) 21. In the space below sketch an unstained and a stained yeast. Identify which is which. 22. Yeast reproduce by a process called budding. Locate and sketch what you feel appears to be a single yeast undergoing the process of budding. 23. As organisms move about under the microscope, they not only change position in the field (move right to left, etc.), but they also appear to move in and out of focus. Why? 24. When seen under high power, do the organisms appear to move more rapidly or more slowly than when seen under low power? Explain why. 25. In the space below sketch one of the moving organisms that you observed showing its appearance before and after