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Unformatted text preview: 2-1 SPRING 2010 NAME ________________________________ BTNY 210 LAB SECTION (Day/Time) ______________ LABORATORY #2(INTRODUCTION TO MICROSCOPES; PLANT CELL STRUCTURE AND DIVISION) Lab #2 Objectives: 1) learn the general parts, their functions and the proper use of the light microscope 2) recognize and know the function of the basic internal structures of plant cells 3) be able to distinguish the phases of the cell cycle and the sequence in which they occurA. MICROSCOPE USE 1. Construction of the Microscope It is important that you become comfortable with these microscopes because you will be using them in labs throughout the semester. Light microscopes are routinely used in laboratory research and teaching to examine features of plants that cannot be seen otherwise, for example, to study the internal anatomy of plant organs. Please ask your instructors for help if you have problems with the microscope. Your instructor will guide you through the construction of the microscope and explain how to turn on and adjust the microscope to view a sample. Your lab handout includes a page illustrating a diagram of a microscope (pg. 2-7) and another page listing the parts of the microscope (pg. 2-6). The letters of each part on the list correspond to the letters on the diagram. Take a few minutes to label each part of the microscope diagram and be sure you can find the same part on your microscope. Answer the following questions about the microscope you are using in today’s laboratory. a) What are the magnifications of the objective lenses on your scope? b) What is the magnification of the eyepieces? c) Total magnification is determined by multiplying the magnification of the eyepiece times the magnification of the objective lens. What is the highest possible magnification of your microscope? 2-2 2. Viewing a Prepared Slide Sample When you are ready to view a sample, first check to be sure the 4X objective is in place. Then pick up a prepared glass slide from the box at your bench and place it on the microscope stage with the stage clip holding it securely. These slides contain sections of Pelargoniumstem. Find a specimen and adjust the following as you look at the image: light intensity coarse and fine focus mechanical stage controls position of the condenser opening/closing of the iris diaphragm Notice the effects of these adjustments on image quality. Ask your instructors if you do not see or understand the effect(s) of a particular adjustment or if you are having any problems seeing a high quality image. Now center the specimen in the field of view and move to the next higher magnification (10X objective). Make any adjustments as necessary to bring the image into focus. Repeat for 20X and/or 40X. However, do NOT use the coarse focus knob at 20X or 40X; use only the fine focus....
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This note was uploaded on 02/23/2012 for the course BTNY 210 taught by Professor Staff during the Spring '08 term at Purdue.
- Spring '08