September 17, 2008

Wednesday Lab

I am writing about the testing of sizes on Paramecium caudatum and bursaria and how they differentiate from one another.

In comparing the two specimen’s size I found that the Paramecium caudatum was larger in size than the bursaria. Paramecia are unicellular organisms and are usually less than 0.25mm in length and covered with minute hair-like projections called cilia. They are characterized by their cilia which are used in locomotion and during feeding. Paramecia feed on bacteria. Paramecia have 2 nuclei, 1 macronucleus and 1 micronucleus. Some have up to 80 micronuclei! The organism cannot survive without macronucleus and cannot reproduce without micronucleus.

I used the 4x on the Parmecium caudatum to measure 11 cells they varied in length from 145.44-199.98um, width wise was 36.36-72.72um. The bursaria was measured at 10x and ranged in length size of 64.8-108um and width wise 36-50.4um. After recording this data I then calculated the mean, mode, median, range and standard deviation. I used the website www.easycalculation.com/statistics to help with these calculations.

To perform this measurements of sizes you would insert a slide into your microscope adjust the focus until you have the specimen in view and using the eyepiece reticle would position each specimen to measure the length and the width of each one that is being counted. To calculate the mean you add up all of the data for each category and then divide the result of the number of specimens. For the median it is the middle value of the data. For the mode it is the most frequently repeated number. The range is just the lowest number and the highest number. The standard deviation is taking the total of the means square root.

Below I have inserted a picture of a Paramecium from the web site www.esu.edu.

paramecium caudatum cell

The sites that I used were:

www.easycalculation.com/statistics

www.esu.edu.

Table 1 – Measurements in ocular units

P. caudatum P. bursaria

lengthwidthlengthwidth

1 94116

2103116

393125

4104136

5102125

6113157

7113116

894155

9103145

1083106

119295

Table 2 – Measurements in microns

Conversion factor used:

P. caudatum P. bursaria

lengthwidthlengthWidth

1 163.6272.7279.243.2

2181.854.5479.243.2

3163.6254.5486.4036

4181.872.7293.643.2

5181.836.3686.4036

6199.9854.5410850.4

7199.9854.5479.243.2

8163.6272.7210836

9181.854.54100.836

10145.4454.547243.2

11163.6236.3664.836

Table 3 – Statistical analysis

P. caudatum P. bursaria

lengthwidthlengthWidth

Mean 175.1356.1987.0540.58

Mode163.6254.5479.236,43.2

Median181.254.5486.443.2

SD343.950.0000360.00010.000016

Max199.9872.7210850.4

Min145.4436.3664.836

Range54.5436.3643.214.4

Table 4 – Calculation of standard deviation for length and width

A. – P. caudatum – length

length(length-mean)(length-mean)2

1 911.5123.92

2106.6713.34

3911.5123.02

4106.6713.34

5106.6713.34

61124.8549.7

71124.8549.7

8911.5123.02

9 106.6713.34

108-29.69-59.38

11911.5123.02

Total185.46

Total/1018.546

SD343.95

B. - P. caudatum - width

length(length-mean)(length-mean)2

1 163.62107.4310.36484443

2181.8125.6111.20758672

3163.62107.4310.36484443

4181.8125.6111.20758672

5181.8125.6111.20758672

6199.98 143.7911.99124681

7 199.98 143.79 11.99124681

8 163.62107.4310.36484443

9181.8125.6111.20758672

10 145.4489.259.447221814

11 163.62107.4310.36484443

Total88.63494264

Total/108.863494264

SD2.977162116

C. - P. bursaria - length

length(length-mean)(length-mean)2

1 79.2-7.85-2.801785145

2 79.2-7.85-2.801785145

3 86.4-0.65-0.806225775

4 93.66.55...