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Unit 1: Intro to Biology
Syllabus Date Classwork Homework
M&M Activity None Handout Course Material and Introduction
Packet – Go over course Meet classmates Handout Unit 1 Packet
Get all packet material signed – due MONDAY Access and download online textbook. Parent email required if any issues occur!
Lab Safety Day! Scientific Method PPT
Begin Scientific Process Worksheet #1 Read and answer questions to 1.1 Introduction to Biology
Finish Scientific Process Worksheet Begin Analyzing the Results of an Experiment
Worksheets
Read and answer questions to 1.2
Finish and go over Analyzing the Results of an Experiment Worksheets
Read and answer questions to 1.3
Begin Graphing Worksheets Complete all Graphing Homework Complete Termite Tracking Lab and go over Go over Graphing Worksheets
Microscope PPT Check online for Study Guide for Test
Lab: Using a Compound Microscope Microscope Colorings – Finish Lab Study for Test
Test Unit 1 and Packet Due
Packet Grade
Assignment Possible Points Your Score
Reading Questions 40
Methods of Science PPT Notes 10
Scientific Process Worksheet 20
Analyzing The Results of an Experiment 20
Graphing Activity 30
Termite Tracking Lab 20
Microscope PPT 10
Microscope Lab 45
Readings
1.1
Before you Read
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2
3
4
1.2
Before you Read
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2
3
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5
1.3
Before you Read
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2
3
4
5
6
7
Methods of Science Notes
Chapter 1 Section 3
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What does this have to do with the scientific method?
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Step 1:
Step 2:◦ Put it in If….Then….
Step 3:
Step 4:
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Design an experiment to test the following observation.
Garlic reduces cholesterol in lab rats.
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Experimental Group
Control Group
In the garlic/rat experiment what is your control group? _________________
In the garlic/rat experimental what is your experimental group?__________________
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Independent variable:
Dependent variable:
Constants:
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Qualitative: ◦ Uses descriptions◦ Pros -Cons
Quantitative:◦ Uses numbers◦ Pros -Cons
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TitleName
Key
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Scientific Process Worksheet #1
1. Name the 4 steps to the scientific process and give an example of each:
2. Explain the limits of science:
Questions 3 and 4 are hypothetical experiments that contain real information. After you read about the experimental design, identify the parts of the experiment as requested following each reading.
3. Hershey’s sells large bags of chocolate scraps to farms as a food supplement for animals. Local Farmer G weighed two groups of ten cows that were the same age and breed, and calculated the average weight per cow. Each day for 90 days, he supplemented only one group’s feed with the chocolate scraps. He weighed all cows once each week on Wednesday and calculated the average weight per cow for each group. The data he kept was the weight gain of the cows. At the end of the quarter, he found that the chocolate-fed cows gained more weight and looked happier than the cows that were not fed chocolate.
a. What was the original hypothesis of Farmer G? _____________________________________
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b. Control Group: _______________________________________________________________
c. Experimental Group: __________________________________________________________
d. Other variables that were controlled: ____________________________________________
e. Independent variable (x axis): __________________________________________________
f. Dependent variable (y axis): ____________________________________________________
g. Which statement is NOT scientific? ______________________________________________
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4. Rooibos (Aspalathus linearis) is African Red Bush “Tea”, but it is NOT tea, it is a tisane (herbal drink) made from a South African legume. It is safe for infants and is used to treat anxiety, headaches, insomnia and hypertension in adults, as well as skin rashes when applied topically. It contains more minerals and anti-oxidants than any tea and it boosts your immune system when used regularly. Tea (Camellia sinensis) can be green (dried), black (dried and fermented), oolong (dried and briefly fermented) or white (leaves picked before they are fully open and buds are covered by fine white hair). Two VHS homeroom classes of 24 students were used in the study. Each student in junior homeroom 144 drank 8 oz. of rooibos each day for the school year. Each student in junior homeroom 336 did not. Every month the students were polled and the total number of absence due to sickness was recorded.
a. What was the original hypothesis about rooibos? ___________________________________
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b. Control Group: _______________________________________________________________
c. Experimental Group: __________________________________________________________
d. Other variables that were controlled: ____________________________________________
e. Independent variable (x axis): __________________________________________________
f. Dependent variable (y axis): ____________________________________________________
g. How would you change the study to improve its validity? ____________________________
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5. A group of college students were given a short course in speed reading. The instructor was curious if a monetary incentive would influence performance on a reading tests taken at the end of the course. Half the students were offered $5 for obtaining a certain level of performance on the test, the other half were not offered money.
a. Independent variable: __________________________________________________
b. Dependent variable: __________________________________________________
c. Experimental group: __________________________________________________
d. Control group: __________________________________________________
6. Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they’re supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. Every 5 minutes, Smithers counts how many stacks of papers each group has made.
a. Control Group: __________________________________________________
b. Independent variable: __________________________________________________
c. Dependent variable: __________________________________________________
d. Make a group of this data:
e. Does Smithers’ Juice work? Explain in 3 or more sentences.
Time (min) # Stacks Group A # Stacks Group B 5 75 85
10 150 180 15 230 270 20 290 300 25 340 350
Analyzing the Results of an Experiment
A group of ecology students was investigating the food chain in a nearby stream last summer and noticed brook trout feeding on mayfly nymphs among the rocks on the stream bottom. Mayfly nymphs are large crawling insects that form one stage in the development of mayflies. The students hypothesized that the trout were reducing the insect population by at least 30%. To test this hypothesis, the students set up a series of wire mesh cages on the floor of the stream. The cages allowed the mayfly nymphs to enter and leave as they pleased, but prevented access by the trout.
They planned to compare the number of insects found under the cages with the number of insects in a nearby section of the stream that did not have cages to keep the fish away. Each week, for five weeks, the students collected and counted all the insects from the protected and unprotected areas of the stream. Table 1-1 shows the results of their experiment:
Table 1-1. Results of Predation Experiment
Number of Nymphs Collected
Caged Areas
Uncaged Areas
Week 1
66
50
Week 2
120
61
Week 3
141
74
Week 4
176
82
Week 5
234
93
Total Nymphs Collected
737
360
Average Number of Nymphs Collected Over the Five Week Period
147.4
72.0
1. Which was the control group in this experiment?
a. The caged areas b. The uncaged areas c. No control group was used in this experiment
2. Using the graph paper in Figure 1-1, graph the results of this experiment. Make sure to Label the horizontal and vertical axes and give your graph a title.
Figure 1-1 3. From Week 1 through Week 5, the number of nymphs collected in both the caged and uncaged areas:
a. increased b. decreased c. remained the same
4. Do the results of the experiment support the hypothesis? Explain your answer.
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Commercial Application for the Scientific Method You are a quality control engineer for a large paper products manufacturer! Several commercial customers have complained that the absorbency of your paper towels does not meet their needs. In an attempt to improve your company's product line, you decide to conduct an experiment to see how your towels compare to your competitor's towels in terms of absorbency.
Describe your experimental setup in detail.
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Graphing Worksheet
1. Title of Graph _____________________________________________ (depth only)
2. Add in axis labels.
3. How long did it take for the diver to descend to 80 feet? ______________________
a. How deep was the diver twelve minutes into the dive? ______________________
4. Between 23 minutes and 25 minutes what rate did the diver ascend at? (hint )
______________________ ft/min
5. How much time did the diver spend between 10-20 feet at the end of the dive? ___________________
6. Title of Graph _____________________________________________ (Temperature)
7. Add in axis labels.
8. What happens to the temperature of the water as depth increases?
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9. The diver forgot to bring some of his equipment. He will become hypothermic at 55 oF. How deep can the
diver go to avoid hypothermia? __________________________
10. What information can you obtain from these graphs? (must be a paragraph) ____________________________________________________________________________________________
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11. Fill in the following charts using Graph 2
Time Depth Temperature 0 5 10 15 20 25 30 35
Homework
1. Using the data to the right, create a time vs. depth graph
2. Using the data to the right, create a time vs. temperature graph
3. How might this graph change if depth were measured every 10 seconds compared to every 2 minutes? ____________________________________________________________________________________________________________________________________________________________________________________________________________________________
a. Using a different color, draw your prediction on your time vs. depth graph.
4. What happened during this dive? Use your graph and this table to create a story explaining what happened. (Must be 3 paragraphs long. Use a separate piece of paper if needed.)
Time (min)
Depth (ft)
Temp. (deg F)
0 0 712 20 654 79 516 80 478 81 47
10 82 4712 82 4714 82 4716 80 4718 80 4720 78 4722 75 4724 62 4726 45 4928 35 5430 25 5332 15 6334 15 6336 11 6438 2 6540 0 65
Termite Tracking Lab Prelab: Part 1 Are termites living organisms? Complete the chart about termites. Use observation and research to help you complete the chart.
Characteristic of Life
Description How a termite does this
Made of one or more cells
The cell is the basic unit of life. Some organisms have only one cell; others have many cells
Displays organization
The organization of a biological system begins with atoms and molecules. Each organized structure in an organism has a specific function. For example, an anteater’s snout is long because it functions as a container for the long tongue
Grows and Develops
Growth results in an increase in mass. Development results in different abilities. For example a tadpole grows larger and develops into an adult frog.
Reproduces Organisms reproduce and pass on traits to the next generation. Reproduction must occur for a species to continue to exist.
Responds to stimuli
Reactions to stimuli from inside and outside the body are called responses. For example, a cheetah responds to the need for food by chasing a gazelle. The gazelle responds by running away.
Requires energy Energy is needed for life processes. Many organisms get energy by taking in food. Other organisms make their own food.
Maintains homeostasis
Homeostasis the process that keeps conditions inside the bodies of all organisms stable. For example, humans perspire when hot to lower body temperature
Adaptations evolve over time
Adaptations are inherited changes that occur over time and help the species survive.
All of the information should be written in complete sentences
Termites have a unique response to a stimulus created by some writing tools. Figure out what their response is, specifically what writing tools act as a stimulus, and why a termite does this.
1. What is your hypothesis about the termite’s movement in relationship to writing tools? _________________________________________________________________________________
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2. Instructions: a. Take a clean sheet of paper (NO writing!). b. Using a paintbrush, gently place termite on the blank sheet of paper. What does it do?
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c. Draw lines, circles or spirals on the paper using the different writing tools. Be sure you note which pen draws the line. Put the termite on the paper and observe what happens. Fill in the table:
3. What is the stimulus that termites respond to? _________________________________________________________________________________
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4. Find the meaning of each concept and explain how you used each in the activity a. Hypothesis
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b. controlled experiment, _______________________________________________________________________________
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Experiment (example use 3 different writing tools)
Reaction of Termite Support /Refute Hypothesis Update your hypothesis as necessary
1.
2.
3.
c. controlled variable (constant) _______________________________________________________________________________
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d. background information _______________________________________________________________________________
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5. Why might it have been worthwhile to have:
a. Used many termites for each experiment _______________________________________________________________________________
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b. Repeat each experiment multiple times _______________________________________________________________________________
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6. Research termites, what is the reason for the termite’s behavior in the lab?
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Clean up your area
Return your living termites to the termite container, if you killed any termites place them in the garbage.
Clean your lab station; wipe down your lab with soap and water.
Microscope Notes
MICROSCOPESTools of Science
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History of Microscope
The compound light microscope was invested by Hans and Zacharias Janssen 1590-1610
The first microscopes were novelty toys sold to the wealthy
The image quality was poor
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Robert Hooke – 1660’s
Chemist, mathematician, physicist, and inventor
Improved the CLM Coined the term
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about him
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Anton van Leeuwenhoek – 1670’s
Wine surveyor, cloth merchant, minor public officer
Used a single lens microscope
Made the best scopes available
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Parts of the Microscope Explained
Ocular Lens The lens you look into Usually a power of 10x
Revolving nosepiece Contains different objectives
Stage Where slides are placed
Stage clips Holds slides in place
Objective lens One of 3 or 4 lenses on a microscopeThey have different powers
Diaphragm Adjusts amount of light illuminating specimen
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To find Total Magnification
Multiple ocular x objective
If the ocular lens is 20x and the objective lens is 100x, what is the total magnification?
If total magnification is 300x and the ocular lens is 100x, what is the ocular lens?
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Stereomicroscope
Contains ________ ocular lenses
Total magnification is under 100x
Gives a 3-D image
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Electron Microscopes
ScanningElectron Microscope Up to 300,000x 3-D image of specimen _____________________
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TransmissionElectron Microscope Highest possible
magnification 2-D image ____________________
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Scanning electron microscope
Sunflower pollen Dust mite
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Microscope Lab
Introduction
The compound microscope is one of the most important instruments used by biologists today. Through observation of microscopic organisms and microscopic structures, scientists have discovered many things about the world around us and how is operates. In this investigation you will learn the basic skills necessary to use the microscope correctly. Knowing these skills will be very helpful and important to your study of biology.
Objectives
1. To name and identify the function of the parts of a compound microscope. 2. To operate a compound microscope correctly. 3. To use a compound microscope for observations under low and high powers.
Materials
• Compound microscope • Stereomicroscope • Scissors • Metric clear plastic ruler • Lens paper • Eye droppers • Microscope slides • Depression slides
• Cover slips • Colored thread slide • Newspaper • *Small plant samples (student supplied) • *Hair samples (student supplied) • *Leaves (student supplied) • *Pond water (student supplied) • *Moss (student supplied)
PART A: INTRODUCTION
1. When a microscope has a double set of lenses (eyepiece and objective) it is called a compound microscope. The total magnification of the microscope can be found by multiplying the number on the eyepiece by the number of the objective. For example, if the magnification of the eyepiece is 5X and the magnification of the objective is 10X, then the total magnification is 5OX.
2. The objectives overlook a flat platform called the stage. The stage has an opening in its center that allows light to enter the microscope. A slide is placed on this stage and kept from moving through the use of stage clips.
3. Underneath the stage is a diaphragm. The diaphragm regulates the amount of light entering the microscope. The diaphragm is adjustable to various accommodate light conditions. On a microscope with an iris diaphragm, a lever controls the size of the opening through which light passes. A microscope with a disc diaphragm is operated by rotating a disc containing various sized openings. Adjusting the diaphragm is as important as correctly focusing a microscope.
4. Your microscope will have a lamp for a light source. Plug it in to check its functioning. Position the cord to be sure it is out of the way.
5. There are usually two pairs of adjustment knobs on a microscope that are used for focusing. The coarse adjustment is the larger of the two knobs. When turned, it moves the body tube up and down in large increments. It should only be used under low power when initially focusing on the object. After the coarse adjustment is used to bring the object into general focus, the fine adjustment is used to fine tune the image. Fine adjustment can also be used for focusing under high powers.
6. The bottom part of the microscope is the base. Make sure that the base is resting securely on the lab bench.
7. Place the microscope in its normal position for use with the arm facing you. Before observing anything under the microscope, you should get it ready for viewing by following these simple steps:
a. Make sure the microscope is secure.
b. Clean the eyepiece and objectives by wiping them with lens paper.
c. Open the diaphragm all the way.
d. Turn the nosepiece until the low power objective clicks into place.
e. Lower the stage to its lowest position.
f. Turn on the light source.
g. Look through the eyepiece with both eyes open to reduce eye strain,
h. If the light is too bright or too dark, regulate it with the diaphragm.
i. If any tiny specks of dust appear, clean the lenses with fresh lens paper.
Questions:
1. Why is it necessary to hold the microscope by the base and the arm?
2. Why must the objective be lined up directly underneath the eyepiece?
3. What is the purpose of the stage?
4. Describe the function of the following microscope parts: a. Objective
b. Revolving nosepiece
c. Stage
d. Coarse adjustment
e. Fine adjustment
5. Why is the microscope called a compound light microscope?
6. Locate the number on the eyepiece. This number indicates the magnifying power of the lens in the eyepiece. What magnification does the lens have?
7. Locate the revolving nosepiece which holds the objectives. Locate the shortest objective. This is the low power objective. What number is written on the low power objective?
a. What does this number mean?
8. Locate the longer objectives. These are the high power objectives. What number is written on the high power objective?
a. What does this number mean?
9. Find the total magnification of the microscope at low power and high power by multiplying the number on the eyepiece and the number on the objective.
a. Total magnification on low power
b. Total magnification on high power
10. What would the magnification of your microscope be if you used a 5X eyepiece and a 60X objective?
PART B - MAKING A WET MOUNT:
1. Cut a small letter "e" from a newspaper article. Obtain a regular, flat microscope slide. Position the "e" right-side up in the center of the slide. Using a dropper, place a drop of tap water over the letter.
2. Obtain a cover slip. Hold the cover slip at a 45° angle and touch one edge to the slide. Slowly lower it onto the water over the letter.
3. Preparing a slide in this manner is known as making a wet mount. If properly done, there should be no air bubble trapped under the cover slip. If this is not the case, start over again. Wet mounts allow you to view living organisms in their natural state.
4. As the water evaporates from the slide, you may need to add water to keep your slide fresh. This is done by placing the dropper to the edge of the cover slip and adding a drop of water, which will run underneath. This is also the technique to use when adding different stains of solutions to a wet mount. If you add too much water, it may be removed by using the corner of a paper towel to soak up the excess water. Never lift the cover slip to add or take away water.
Questions:
1. What is the purpose of wet mounts?
2. Why do you think wet mount preparations must be made very thin?
PART C - LOW POWER:
1. When observing a specimen under low power, the following steps should be taken:
a. Ensure the microscope is adjusted in the starting position as instructed in Part A with the low power objective in position and the body tube is raised to the highest level.
b. Place the slide with the letter "e" on the stage and secure with the stage clips. Be sure that the "e" is not upside-down and is centered over the opening in the stage.
c. While looking at the microscope from the side, NOT through the eyepiece, lower the body tube until it stops. Most microscopes have an automatic stop on low power.
d. Look through the eyepiece and raise the body tube using the coarse adjustment until the letter "e" comes into focus. Center the letter in the view and use the fine adjustment to bring it into better focus.
e. Look at the distance between the slide and the objective. This is called the working distance.
f. Adjust the diaphragm to control the amount of light.
2. While observing through the eyepiece under low power, move the slide to the right and to the left. Observe what happens. Then move it towards you and away from you. Observe what happens.
Questions
1. Draw your letter "e" as it appears through the eyepiece.
2. In what three ways is the image of the letter "e" different through the microscope as compared to how it is positioned on the slide on the stage?
3. When you move the slide from left to right, in what direction does the letter move?
4. When you move the slide away from you, in what direction does the letter seem to move?
5. The distance between the slide and the objective is called the _________________ .
____________X
PART D - HIGH POWER
1. When observing a specimen under high power, these steps should be taken:
a. Always position the specimen in the center of the field of view and use the coarse adjustment under low power first.
b. Open the diaphragm all the way. As you increase the magnification, it becomes necessary for light rays to travel through additional lenses. Therefore, more light is needed to avoid a dark field.
c. Turn the nosepiece until the high power objective clicks into place. Most microscopes are parfocal. This means that an object focused under low power will be approximately focused under high power.
d. Under high power, all focusing is done only with the fine adjustment. Not more than one turn either way should be needed for a sharp focus.
e. Look at how small the working distance is on high power. USING THE COARSE ADJUSTMENT MAY CRACK THE SLIDE OR CAUSE DAMAGE TO THE OBJECTIVE LENS.
Questions:
1. Sketch the "e" as you it under high power.
2. When you changed from low to high power, how did the working distance change?
3. When you changed from low to high power, how did the size of the field of view change?
4. Why must you never use the coarse adjustment to focus under high power?
5. Why should you always locate an object under low power before switching to high power?
6. Define the term parfocal.
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PART E - DEPTH OF FIELD AND RESOLUTION
• Depth of Field is the vertical thickness of specimen that can be in focus at one time.
• Resolution is the ability of a microscope to show fine details clearly. Resolution is just as important as magnification. To merely magnify a blur does not tell anyone more about it. The ability of a microscope to resolve very closely spaced objects depends on the quality of the lenses and the wavelength of the light being used.
Instructions:
1. Obtain a prepared slide of colored thread.
2. Observe under low and high power.
3. Obtain a hair from your head. Prepare a wet mount. Observe under low and high power.
Questions:
1. Draw the slide of colored thread under low and high powers. Show the details!
2. Draw the hair under low and high powers. Show the details!
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PART F - USING A DEPRESSION SLIDE A depression slide is a special microscope slide that is designed to hold a drop of liquid containing live organisms. It can be identified by the circular, depressed area in the center of the slide.
1. Obtain a depression slide. Place a drop of pond water in the circular area. Cover with a cover slip.
2. Observe under low and high power.
3. Draw what you see.
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PART G - COMPARING THE STEREOMICROSCOPE TO THE COMPOUND MICROSCOPE
A stereomicroscope can be identified easily because it has two eyepieces, where a compound microscope only has one.
1. Obtain a stereomicroscope, turn on the light and determine how its uses differ from the compound light microscope.
2. Put a piece of moss on a paper towel and put it on the stage of the stereomicroscope. Using the adjustments to focus on the moss.
3. Draw your observations.
4. While looking through the eyepieces, move the paper towel to the left.
5. Observe the working distance for the stereomicroscope.
6. Compound light microscopes work by having light pass through the object being viewed. However, not all objects are translucent.
7. Place a leaf under the stereomicroscope.
8. Draw your observations.
Moss Leaf
____________X ____________X
Questions:
1. If you move an object to the left under a compound light microscope, it appears to move to the right. In what direction did the moss appear to move under the stereomicroscope?
2. How does the working distance of a stereomicroscope compare to the compound light microscope?
3. How does this affect the size of objects that can be viewed under the stereomicroscope?
4. Compound light microscopes work by having light pass through the objects to be viewed. However, not all objects are translucent. If an opaque object is viewed through a compound light microscope, what will you see?
5. How does shining the light of the stereomicroscope on the moss allow you to view it in different ways that under the compound light microscope?
6. Why do you think objects look three dimensional under the stereomicroscope?
PART G-CLEAN Up:
1. Dry the microscope completely.
2. Be sure the low power objective is in position over the stage and the body tube is all the way down.
3. Wrap the cord around the base, cover it and return it to the cabinet.
4. Clean, dry and put away all slides and other materials used.
