Laboratory Study Guide

The Microscope

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Terms to Know in This Chapter:

compound microscope

dissecting microscope

eyepiece

ocular

body tube

revolving nosepiece

objective

stage

coarse adjustment

fine adjustment

substage condenser

iris

iris diaphragm

color aberration

arm

base

mechanical stage

stage clips

light source

scanning objective

low power objective

high power objective

oil immersion objective

phase-contrast

parfocal [par FOK ul]

resolution

magnification

light intensity

prepared or permanent slide

wet mount or temporary slide

glass slide

cover slip

stain

cyclosis [cy CLOSE siss]

plasmolysis [plaz MOLL eh siss]

protoslo

micrometer (sing.) [my CHROM eh tur]

lens paper

lens cleaner

chloroplast

central vacuole

nucleus

What You Need to Know:

You should be able to:

1. name the parts of the compound microscope and explain the function of each part,
2. distinguish between resolution and parfocal,
3. explain color aberration in your scope,
4. distinguish the functions of the iris and substage condenser,
5. name the objectives on the microscope, give their magnification and tell whether the objectives are sealed or unsealed for immersion use,
6. calculate the magnification using the eyepiece in conjunction with any objective,
7. estimate the size of the object you are viewing in micrometers,
8. demonstrate the proper way to clean a microscope and properly put away a microscope,
9. demonstrate how to focus a microscope on an object and shift between magnifications without damaging the scope or the slide,
10. explain the difference between prepared and temporary slides and demonstrate the ability to make a temporary slide and stain the slide correctly,
11. explain what happens to an image in your field of view when you move the stage up, down, left or right,
12. explain what happens to the amount of light entering the microscope as you increase magnification,
13. demonstrate the ability to focus on the letter "e" on a prepared slide on scanning, low, and high power and be able to shift back and forth between magnifications,
14. determine which color thread lies atop another thread by using depth perception and fine adjustment focusing, and,
15. recognize the parts of a plant cell as demonstrated by Elodea and, define cyclosis and plasmolysis as it relates to Elodea.

Exercises: Fill in the Blank.

1. The ability to distinguish or discriminate details in a microscope is called .
2. With which objective should you begin all microscope work?
3. With the microscope you are using in the laboratory, what is the magnification ability of the high power objective by itself?
4. With the microscope you are using in the lab, what is the magnification of the high power objective in conjunction with the eyepiece or ocular?
5. What part of the microscope takes a wide beam of light and narrows it down?
6. What part of the microscope regulates the "intensity" of light?
7. As you increase magnification in a microscope, what must you do to the light intensity of the scope?
8. Which is the only objective that is "sealed" on the microscope?
9. You must always carry a microscope in the upright position with one hand on the and one hand on the .
10. When you move an object you are viewing under a microscope up with the mechanical stage, in which direction does it move in your field of view?

Exercises: Multiple Choice. Select the Best Answer.

1. Which objective should be directly over the hole in the stage when putting your microscope away?
   (1) any objective will do
   (2) scanning objective
   (3) low power objective
   (4) high power objective
   (5) oil immersion objective
   
   
2. What does the term "parfocal" mean?
   (1) the image will be color corrected
   (2) the image will not be color corrected
   (3) the ability to discriminate between two points
   (4) the ability to go from one magnification to another using only the fine adjustment
   (5)the ability to go from scanning to high power without using low power
   
   
3. If an eyepiece has a magnification of 15X and the objective has a magnification of 100X, what is the total magnification of the object?
     (1) 15X
     (2) 115X
     (3) 150X
     (4) 1500X
     (5) 15000X
   
   
4. The apparent flowing or movement of cytoplasm within a cell is called:
     (1) plasmolysis.
     (2) crenolysis.
     (3) hemolysis.
     (4) cyclosis.
     (5)turgor.
   
   
5. Which is a true statement about your microscope?
     (1) Begin all microscope work with the scanning objective over the hole in the stage.
     (2) Make sure the body tube is locked into the closest position to the objective.
     (3) Make sure the iris diaphragm is all the way closed.
     (4) All of the above are correct.
     (5) None of the above are correct.