Name: ____________________________________________________ Period: ____________

.Part D – The Simulation

.

The purpose of this part of the webquest is to simulate DNA fingerprinting and determine which of your classmates threw the gum. For the purposes of this simulation we shall consider the restriction enzyme Alu I which makes a blunt cut between the G and C in the DNA sequence shown below.

AG CT TC GA For example given the following DNA sequence, the Alu I enzyme would make two cuts resulting in three pieces with sizes of 2, 9 and 5 base-pairs each.

AG CTCGGTCAG CTACA TC GAGCCAGTC GATGT 2

9

5

On the following page are 'DNA' samples from four sources, the three students and the gum. Scan each piece of DNA for the Alu I restriction site. After locating any/ all of the possible locations that this particular restriction enzyme will cut each sample, make note of the total of number of fragments produced from each the sample. Additionally, for each digest, make note of the length of the individual fragments for each DNA sample.

Use the data obtained from the digestion (cutting) of the four DNA samples with the restriction endonuclease Alu I to make check marks indicating the positions of the bands on the gel after applying the electric current to the setup.

Construct a brief summary of the results addressing the following:   

Who threw the gum? What evidence leads to that conclusion? Why did Dr. N hand out envelopes?

DNA Sequences

Gum

AGCACCAGCTTCGTAAAGCTGGCCAGCT TCGTGGTCGAAGCATTTCGACCGGTCGA

Student 1

TTCGATAGCTCGAGCTGGAGCTAGCTGG AAGCTATCGAGCTCGACCTCGATCGACC

Student 2

AGCTTAGCAGCTGGGTAAAGCTGGCCTA TCGAATCGTCGAC CCATTTCGACCGGAT

Student 3

AGCACCAAGCTCGTAAAGCTGGCCCAGC TCGTGGTTCGAGCATTTCGACCGGGTCG

Name: _____________________________________________________ Period: ____________

.

Electrophoresis Data

.

Place a check in the box to represent that there is a fragment of DNA of a particular length (based on the scale) for that lane. If a lane has more than one fragment of the same number of base pairs, only enter a single check for that size.

Electrophoresis Data # OF BASE PAIRS

Gum

Student 1

Student 2

Student 3

Negative End

10

9

8

7

6

5

4

3

2

1 Positive End

Conclusions: