Lab Report Zoology 2

7/30/2019 Lab Report Zoology 2

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Roxanne Diane R. UyMST BIO

MICROSCOPE AND MICROMETRY

ACTIVITY # 2

I. Introduction

A. BackgroundMicroscopes are intended to measure small objects. Size is one ofthe things needed to be measured using microscope, which can beachieved by using the rulers of a microscope-ocular and stagemicrometer. The ocular micrometer (see Figure 1-A), known as anarbitrary ruler, has no assigned unit since the size of a magnifiedimage will change depending on the objective being used.

Therefore, it must be calibrated with a stage micrometer (see Figure1-B), for each of the objective lens, in order for it to have aquantitative value. A stage micrometer is considered to be the true

ruler, since it has units (millimeters (mm) or micrometers (m)).When calibrating, one will line up the stage micrometer with theocular micrometer and count the number of divisions on the ocularmicrometer per millimeter or micrometer on the staged micrometer.The number of divisions will change as the magnification changes.

A B C

Figure 1. A-Ocular micrometer, B- Stage micrometer, C- Ocularmicrometer superimposed on a stage micrometer

B. Question

Q1: What is the relationship of magnification of the objective lens(A) with the calibration constant of the micrometer (B)?

C. Objective

To determine the importance of calibration in doing accuratemeasurement

To establish the relationship of magnification of the objectivelens and the calibration constant of the micrometer.

D. Hypothesis

H0: There is no significant relationship between A and B

H1: There is a significant relationship between A and B

II. Materials and Method

A

B CFigure 2. Materials used for the activity. A-Compound microscope,

B- Stage micrometer, C- Ocular micrometer


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Obtain a stage and ocular micrometer (see Figure 2). Place the stagemicrometer on the stage of the microscope. Rotate one of themicroscope eyepieces until the lines of the ocular micrometer areparallel with those of the stage micrometer. Match the lines on the left

edges of the two micrometers by moving thestage micrometer so thatthe graduations of the ocular micrometer aresuperimposed over those of

the stage micrometer. Determine the number of ocular micrometerspaces that fall within a given number of stage micrometer spaces.Calculate the distance between each ocular graduation by using thefollowing formula:

1 ocular micrometer space (m) = x spaces on the stage micrometery spaces on the ocular micrometer

Repeat the procedure for the 10X, 40X, and 100X objectives and recordresults. After acquiring the result for all objective lens, compute thecalibration constant using the following formula:

Calibration Constant = Stage Micrometer x 0.01mmOcular Micrometer

III. Results and Discussion

Table 1. Average calibration constant per magnification of theobjective lens of 13 students

CalibrationConstant

Objective Lens

Scanner(4x)

LPO(10x)

HPO(40x)

IOI(100x)

Mean 25.1 10.1 2.5 1.0

Table 2. Result of Pearson Correlation of the CalibrationConstant and the Magnification of Objective Lenses

Pearson Product Moment Correlation

Statistic Variable X Variable Y

Mean 38.5 9.675

Biased Variance 1446.75 91.211875

Biased Standard Deviation 38.03616699931799.55049082508329

Covariance -362.85

Correlation -0.749145117857612

Determination 0.561218407609895

T-Test -1.5993987470537

p-value (2 sided) 0.250854882142388

p-value (1 sided) 0.125427441071194

Degrees of Freedom 2

Number of Observations 4
http://www.xycoon.com/arithmetic_mean.htmhttp://www.xycoon.com/biased.htmhttp://www.xycoon.com/biased1.htmhttp://www.xycoon.com/covariance.htmhttp://www.xycoon.com/pearson_correlation.htmhttp://www.xycoon.com/coeff_of_determination.htmhttp://www.xycoon.com/ttest_statistic.htmhttp://www.xycoon.com/ttest_statistic.htmhttp://www.xycoon.com/coeff_of_determination.htmhttp://www.xycoon.com/pearson_correlation.htmhttp://www.xycoon.com/covariance.htmhttp://www.xycoon.com/biased1.htmhttp://www.xycoon.com/biased.htmhttp://www.xycoon.com/arithmetic_mean.htm


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Figure 3. Shows the Magnification of the Objective Lens against the

averaged calibration constant

Table 1 shows the magnification of the different objective lens, fromthe lowest (Scanner-4x), to the highest (IOI-100x). Mean of thecalibration constant is also shown having a downward trend.

To test for the relationship of the two variables, Pearsonsrelationship was used. Table 2 gives a correlation result of -0.749145117857612 . A linear relationship was established. To addup, a negative coefficients tell us that there is an inverse relationship:when one variable increases, the other one decreases. A result of -.70or higher indicates a very strong negative relationship between the 2variables.

IV. Conclusion

Based on the results, I therefore reject the null hypothesis and acceptthe alternative hypothesis-magnification and calibration has a strong

relationship. As the magnification of the objective lens increases, thecalibration constant decreases, establishing a inverse relationshipamong the two. OBJECTIVES

V. References

Agar Scientific (n.d.). Calibration standards and specimens.Retrieved July 8, 2013, fromhttp://www.agarscientific.com/media/import/03_Calibration_Standards_pgs_39-84_date_17_06_10_web.pdf

City College of San Francisco (n.d.). Quantitative microscopy.Retrieved July 8, 2013, fromhttp://fog.ccsf.cc.ca.us/dvandepo/documents/microscopy_quant.pdf

Damon, A. W. (2011). Micrometer eyepiece. Retrieved July 8,2013, from http://www.mr-damon.com/experiments/1ib_bio/micrometer.htm

DoctorFungus (n.d.). Ocular micrometer. Retrieved July 8, 2013,from http://www.doctorfungus.org/thelabor/sec11.pdf

Gardner, D. (2007). Measuring with a microscope.Retrieved July 8, 2013, fromhttp://www.ccmr.cornell.edu/ret/modules/documents/MeasuringwithaMicroscope.pdf


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Leica DME, & Idaho State University (n.d.). Microscope use.Retrieved July 8, 2013, fromhttp://www.isu.edu/departments/biolab/Training/Microscopes.pdf

Microtec Microscopes (n.d.). Calibration of microscope eyepiecegraticule. Retrieved July 8, 2013, fromhttp://www.tecmicroscopes.co.uk/Downloads/Microtec%20-%20graticle%20calibration.pdf

Phillips Community College (n.d.). The microscope. Retrieved July 8,2013, fromhttp://www.biologyjunction.com/Microscope%20Lab.pdf

Pyser SGI (2005, September 6). Stage Micrometers. Retrieved July 8,2013, from http://www.pyser-sgi.com/images/thumbnails/Graticules/Stage%20Micrometers%20web.pdf

University of Cambridge International Examinations (2006). TeachingAS biology practical skills. Retrieved July 8, 2013, fromhttp://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_nos_ps_2.pdf

Wessa P., (2012), Pearson Correlation (v1.0.6) in Free StatisticsSoftware (v1.1.23-r7), Office for Research Development andEducation, URL http://www.wessa.net/rwasp_correlation.wasp/

Zeiss (1998, January). Standard 25 ICS transmitted light microscope.Retrieved fromhttp://www.zeiss.com/C1256F8500454979/0/093ADF7003182351C1256F8F00392651/$file/b-40-029standard25_ics.pdf

Lab Report Zoology 2

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