2. List two reasons that this is a picture of a section of DNA and not RNA..
This lab was originally created by Susan Offner and is part of the Access
Excellence Collection.
All credit is given to her for this original idea which I have modified for my
AP Biology class.
| 1. How many nucleotides are represented in this picture? 2. List two reasons that this is a picture of a section of DNA and not RNA.. |
|
The following is the base sequence on one strand of a DNA molecule:
T A C G C C A G T G G T T C G A T C
3. Give the base sequence of the complementary DNA strand.
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4. Give the base sequence of the strand of mRNA read from the original
DNA strand.
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5. What protein fragment would this mRNA code for?
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You need the chart for the genetic code for mRNA codons to do this.
You can
obtain this by clicking here.
6. The original DNA strand serves as a template.
What does the term template mean?
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Note the original DNA strand below:
T A C G C C A G T G
G T T C G A T C
** The fragment of the leading strand of the DNA molecule discussed
previously has now undergone
a mutation so a G has been added to the original DNA strand after the 3rd
nucleotide.
Use this new DNA sequence to answer the questions 7-9
which follow below the new sequence.
T A C G G C C A G T G G T T C G A T C
7. What would the mRNA base sequence coding from this new DNA strand look like?
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8. What would the resulting protein look like? (the amino acid sequence)
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9. This type of mutation is called a frame shift mutation.
Explain what this means
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A mutation occurred to change the 8th nucleotide in the original DNA strand
from G to C. Use this strand indicated below to answer the questions
which follow:
T A C G C C A C T G
G T T C G A T C
10. What would the base sequence of the resulting mRNA be from
this strand?
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11. What would the resulting protein look like?
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12. This kind of mutation is called a point mutation.
Explain what this means.
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13. Provide an example of a point mutation that would not cause
a
change in the protein
synthesized.
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14. Why are frame shift mutations usually more dramatic than point
mutations?
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15. Provide an example of a circulatory condition you have
studied previously in humans caused
by a point
mutation.
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16. What do we call any change in the nucleotides in the DNA molecule?
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17. How do nucleotide changes generally influence the protein formed
from the code?
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18-22. What is the purpose of the laboratory technique known as gel
electrophoresis?
Discuss
in a paragraph why this technique is able to separate fragments of DNA.
Include
the following information in your response:
-- the role of restriction enzymes in preparing the DNA sample to be analyzed
-- the purpose of the agar gel and the holes or wells in the gel
-- the purpose of the weak electric current
-- how the molecular structure and bonding within DNA allows it to be separated
by an electric current
-- the relationship between the length of the DNA fragment and the distance it
travels in the electrophoresis
For hint to questions # 18-22, feel free to view the following:
Electrophoresis PowerPoint One
Electrophoresis PowerPoint Two
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22-24. You must visit the DNA
profiling simulation web site and write a minimum 60 word
narrative about the investigating the will scenario
before handing in this lab. Explain why
in your narrative why you know two of the children are children of both parents,
but that
Alistair is only Percy's child.
Note: You may need to
download Macromedia flash 7 to view this simulation.
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25. Explain how the results of a gel electrophoresis could prove
the
mutations occurring in questions 8
and 10 above actually occurred.
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