BOT-11-Laboratory-2.pdf

BOT 11 Laboratory Name: ______________________________________________ Date: __________ Course and Yr._________________________________________ Score: _________ LABORATORY ACTIVITY No. 2...

BOT 11 Laboratory Name: ______________________________________________ Date: __________ Course and Yr._________________________________________ Score: _________ LABORATORY ACTIVITY No. 2 The Compound Microscope I. Introduction The compound microscope is one of the most important instruments in the study of biology. Hence, the student should be familiar with the different parts of microscope but should also understand the functions of each of the parts and of course how to manipulate or operate the microscope properly. All throughout the course the microscope is used in examining cells, tissues and organs of each of the plant materials handled. A. Parts of microscope and their functions. 1. Base: Y or U-shaped stand that supports the microscope 2. Pillar: A short piece of metal attached to the end of the base. It also supports the microscope. 3. Handle or Arm: The curved metallic part arising from the pillar. Used to hold the microscope. 4. Inclination Joint/Screw: Found at the junction of the pillar and the handle. Used to tilt the microscope. 5. Body tube: The cylindrical structure vertically arising from the handle. It holds the dust shield and nosepiece with the objectives at the lower end. 6. Draw tube: The upper smaller end of the Body Tube bearing the eyepiece or ocular. 7. Revolving nosepiece: the circular structure at the lower end of the body tube to which the objectives are attached. 8. Dust shield: A thin circular structure above the nosepiece used to protect the lenses of the objectives. 9. Adjustment Knob. Two pairs of wheels attached to either side of the body tube: a. Coarse Adjustment Knob: The bigger wheel used to adjust low power objective in focusing. b. Fine adjustment Knob. The smaller wheel used for delicate focusing in connection with the high power and oil-immersion objectives. #16S Quiling Sur, City of Batac, Ilocos Norte [email protected] www.mmsu.edu.ph  10. Stage. The square or circular platform with an opening at the center while the slide is placed during focusing. 11. Clips. The paired structures on either side of the stage used to hold the slide in place. 12. Mirror Rack. Found below the stage and attached to the pillar used to hold the mirror. 13. Ocular or Eyepiece. Found at the draw tube through which the observer peeps during actual focusing. 14. Objectives: The tube-like structures attached to the revolving nosepiece a. Scanner. The shortest tube that forms a whole view of the specimen b. Low Power Objective (LPO). Slightly longer tube that forms a bigger image of the object c. High Power Objective (HPO): Next longer tube that gives a much enlarged and more detailed view of the specimen. d. Oil immersion Objective: Another objective as long as the HPO but with a much bigger degree of magnification. Usually used when studying microorganisms. The lens is used with an immersion oil or cedar oil. 15. Mirror. Found below the stage near the base provided with concave and plane surfaces. Used to collect and direct light to the object. 16. Iris diaphragm. Found below the stage consisting of regularly arranged circular blades. The opening could be adjusted to regulate the amount of light reflected by the mirror on the object. 17. Condenser. A lens found immediately beneath the hole of the stage. Used to concentrate light rays into the specimen. B. Proper care for the Microscope The compound microscope is a very expensive instrument hence it should be handled with extra care. The following precautions on its care: 1. Keep the microscope clean, dry and free from dust. When not in used, keep it covered. 2. When carrying to a short distance, grasp the arm of the microscope with one hand and the bottom of the base with the other hand. Avoid sudden jars with the table. 3. Never touch the lenses with your fingers. Dirty lens is wiped cleanly with a lens paper. 4. Avoid all violent contact of the front lens with the slide or cover glass. Never force the microscope. 5. All adjustments should work freely and easily. Avoid unnecessary turning of the coarse and fine adjustment knobs. 6. Before returning the microscope, see to it that the objective with the lowest linear magnification is in place, the body tube fully lowered, the mechanical stage does not extend beyond the edge of the stage and the mirror place in a vertical position. 7. Before using the microscope at the beginning of any laboratory period, check it for any detect or damage and immediately report to the instructor. You will be held responsible for any damage or missing parts after checking. #16S Quiling Sur, City of Batac, Ilocos Norte [email protected] www.mmsu.edu.ph  C. How to use the microscope 1. Place the microscope close to the edge of the table. Select a suitable stool so that when you are seated and would look into the eyepiece, your back is straight and your neck bent at the nape. With the 10x objective in place, look into the eyepiece with both eyes open. Move the mirror around and select the surface and angle that gives the best illumination in the field of vision. The field of vision is the circular area seen in the eyepiece. Do not tilt the microscope. 1. Delineate the mechanical and magnifying parts of the microscope. _________________________________________________________________________ _________________________________________________________________________ _________________________________________________________________________ _________________________________________________________________________ _____________________________________________________ 2. DRAW AND LABEL THE 17 PARTS OF THE MICROSCOPE. Note: All labels must be at the right side #16S Quiling Sur, City of Batac, Ilocos Norte [email protected] www.mmsu.edu.ph  BOT 11 Laboratory WORKSHEET LABORATORY EXERCISE 2: THE COMPOUND MICROSCOPE #16S Quiling Sur, City of Batac, Ilocos Norte [email protected] www.mmsu.edu.ph #16S Quiling Sur, City of Batac, Ilocos Norte [email protected] www.mmsu.edu.ph