Did Whoo-ville get grinched again?
It was Christmas eve in the land of Who. All the people of Who-ville were snug in bed
waiting for the joys that Christmas morning would bring. At dawn, all the Whos could be
heard going boo-hoo-hoo. How could the Grinch have grinched us again?
Off the angry mob went to to MarthaWho’s house to confront the Grinch. Remember that
last Christmas Martha broke up with the Mayor of Who-ville to marry the Grinch. The
Grinch was clueless about what had happened but the evidence was against him. All the
gifts were still under his tree. His little grinchy-who children had gifts.
The Who-ville police were there to arrest him on the spot, but his oldest grinchy-who said,
“Wait let’s use DNA evidence to find who framed my grinchy dad!” So the police gathered
the evidence and went to the crime lab. The mayor still had the Grinch arrested just in
case he decided to run to Mount Crumpet.
The DNA was analyzed using Gel Electrophoresis technology. The crime scene DNA would
be compared to the Grinch’s DNA and that of 3 other suspects who might want to get back
at the Grinch. The Mayor, of course, for the loss of Martha. The Postman who for years
suffered at the hands to the Grinch’s chaos in the mail room where Cindy-who found him
last year. Lastly his faithful dog Max who endured years of abuse from the Grinch.
AS the restriction enzymes cut the DNA into fragments to be compared everyone
wondered who had grinched Who-ville.
Your task is to analyze the evidence and report to the police.
Step 1: The DNA needs to be cut by the restriction enzyme (as indicated by the lines
slicing them between the lines). Look for the pattern CCGG. Then mark a line between the
CG.
Step 2: Count the base pairs in each fragment and shade in the box for the number of
base pairs present on the template for the gel electrophoresis chart.
Step 3: Repeat this for each suspect until all the DNA has been recorded on the
electrophoresis chart.
Step 4: Analyze the data. Look for similarities between the crime scene and the suspects.
Step 5: Answer the analysis questions
Questions
1. Who ruined Christmas for the Whos ? _________________________________
2. A restriction enzyme cuts at selection points to produce varying lengths. How was
this represented in the lab?
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3. What did you notice about the shorter fragments?
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4. DNA is negatively charged. So based on your understanding of positive and negative
charges, all the base pairs are migrating toward which charge.
_________________
5. What is the purpose of gel electrophoresis?
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6. The function of Polymerase Chain Reaction is to amplify the little bit of DNA so it
can be compared. What DNA had to be amplified so it could be compared?
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