Name:
Date:
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LABORATORY REPORT
EXERCISE #1: STRUCTURE OF DNA
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1. List the three components of a DNA nucleotide.
A.
B.
C.
2. Identify which of the space-filling structures correspond to the three parts of a nucleotide you
listed above.
3. Fill-in the table below with the two base pairs found in DNA and indicate how many hydrogen
bonds hold each pair together.
Base Pair
Number of Hydrogen Bonds
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4. Place the name of each base in the spaces provided and indicate if each is
pyrimidine?
purine or
5. Indicate where the backbone is located on the single-strand of DNA listed below. What is the
name of the covalent bond that connects the nucleotides? Indicate one of these bonds with an
arrow.
6. Using one of the colored pencils provided, color
the inside of the deoxyribose molecules.
A. Which carbon is bonded to the base?
B. Which carbon atoms are bonded to the phosphates?
7. Dr. McDonald’s Seal of Approval for DNA helix
construction.
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EXERCISE #2: SUPERCOILING EUKARYOTIC DNA
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8. If each different color represents a different histone, how many different histones are needed
to form a nucleosome? What are the names of these histones?
9. How many total histones are present in each nucleosome?
10. What kind of chemical interaction is keeping the DNA attached to the histones?
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EXERCISE #3: DNA REPLICATION
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11. Carefully pick up the single strand of DNA. Starting from top left to bottom right, how many
nucleotides (bases) are present in the model? How many are purines and how many are
pyrimidines are present in the model?
12. What is the direction of this single strand of DNA?
13. If this single strand was replicated what would be the direction of the copied strand? Would
this be a leading or lagging strand?
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14. After watching the video on DNA replication and answer the following questions.
A. DNA synthesis of both strands occurs in what direction?
B. What is the direction of the leading strand?
C. What is the direction of the lagging strand?
D. What is an Okazaki fragment and in what direction is it synthesized?
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EXERCISE #4: DISCOVERY OF THE STRUCTURE OF DNA
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15. After reading Watson and Crick’s original paper, write a short essay (1-2 paragraphs) as a
group, describing:
A. The technique used to determine the structure (feel free to do a quick online search)
B. What you consider to be the important findings that they describe.
C. Use the paper provided and stable it to the lab report
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