Name ______
Chapter 12: DNA
Section 12-1: Identifying the Substance of Genes
1. Explain what Griffith did with his experiment with mice and pneumonia.
2. What surprise results came out of Griffith’s experiment?
3. Explain what Griffith meant by the bacteria being transformed (transformation).
4. How did Avery and his colleagues expand on Griffith’s transformation experiment?
5. What conclusion did Avery and the other scientist make about bacterial transformation?
6. What are bacteriophages and what are they made out of?
7. Label the diagram of a T4 bacteriophage shown.
8. Summarize Hershey and Chase’s experiment with bacteriophages.
9. What conclusion did Hershey and Chase develop as a result of their experiments with bacteriophages?
10. Simply put, what is DNA?
11. What are the three critical functions of DNA?
a.
b.
c.
Section 12.2: The Structure of DNA
12. What are the units (monomers) that make up DNA? ______
13. What are the three parts of a nucleotide? Label the diagram of the nucleotide given.
14. Read the bottom of page 345: Analyzing Data. This was an experiment conducted by Erwin Chargaff. You can see his results with 5 different organisms. What conclusion would you have drawn if you were Chargaff about how the bases bond together. This will forever be known as Chargaff’s rule.
a. ______bonds with ______
b. ______bonds with ______
15. How did Rosalind Franklin contribute to the understanding of the shape of DNA using the X-ray diffraction photo taken by her in the 1950’s?
16. Identify the contributions of Watson and Crick in cracking the genetic code.
17. Who provided the main information (not voluntarily) to Watson and Crick that enabled them to figure DNA out? ______.
18. DNA is a double ______and is ______meaning that the two strands run in opposite directions.
19. What type of bond is holding the nitrogenous bases (base pairs) together in the center? ______bonds
20. What would have happened if the bonds between the base pairs were held together by stronger bonds like covalent bonds?
21. Label the diagram of DNA given below. Fill in the missing nitrogenous base
Section 12.3: DNA Replication
22. Before a cell divides, the ______must first be copied.
23. Why are DNA strands said to be complimentary?
24. What occurs during DNA replication?
25. When DNA is replicating, after it unzips, exposing the bases, if the base is Thymine, ______will bond with it. If the base is Cytosine, ______will bond with it.
26. If one strand of DNA has the base sequence of ACTCAT, the new strand that will compliment it when formed will be ______.
27. Identify the enzyme that plays a major role in DNA replication by joining individual nucleotides together to produce a new complimentary strand of DNA. ______
28. Using Figure 12-8 as a guide, label the parts of DNA replication.
29. Look at Figure 12-10 and examine the eukaryotic DNA replication. How does DNA replication in eukaryotic cells differ from DNA replication of prokaryotes?