CHAPTER 16

THE MOLECULAR BASIS OF INHERITANCE

OBJECTIVES
1. Explain why researchers originally thought protein was the genetic material.*
2. Summarize experiments performed by the following scientists:*

a. Griffith, Avery.
b. Hershey and Chase.
c. Chargaff.
d. Franklin and Wilkins
e. Watson and Crick.

3. List the three components of a nucleotide.*
4. List the nitrogenous bases found in DNA and distinguish between a pyrimidine and a purine.*
5. Explain how Watson and Crick deduced the structure of DNA and describe what evidence they used.*
6. Explain the "complementary base-pairing rule" and describe its significance.*
7. Describe the 3-D structure of DNA and explain what kind of chemical bond holds the two strands together.
8. Define, in your own words, semiconservative replication.*
9. Describe the process of DNA replication and explain the role of helicase, single strand binding protein, DNA polymerase, ligase and primase.*
10. Explain what energy source drives endergonic synthesis of DNA.*
11. Define antiparallel stands and explain why continuous synthesis of both DNA strands is not possible.*
12. Distinguish between the leading strand and the lagging strand.*
13. Explain how the lagging strand in synthesized when DNA polymerase can add nucleotides only to the 3’ end.*
14. Explain the role of mismatch repair enzymes in DNA proofreading and repair.*

15. Explain the role of excision repair enzymes and how they differ from mismatch repair enzymes.*
16. Explain the terms complementary strands, antiparallel strands, and complementary base pairing.*
17. Explain the possible effects of mutations and their frequency of occurrence. *

18. Explain the role of telomeres, where they are located, and their role in the cell.

19. What is the role of telomerase enzyme? Where is it found?

KEY TERMS
 Frederick Griffith, transformation, bacteriophage, Alfred Hershey, Martha Chase, Erwin Chargaff, Chargaff’s rules, James Watson, Francis Crick, Rosalind Franklin, Maurice Wilkins, nucleotide, nucleic acid, deoxyribose, nitrogen base, purine, pyrimidine, adenine (A), thymine (T), guanine (G), cytosine (C), nucleoside triphosphate, antiparallel, semiconservative replication, origin of replication, replication fork, replication bubble, helicase, single-strand binding protein, primer, primase, DNA polymerase, Okazaki fragment, leading strand, lagging strand, ligase, mismatch repair, excision repair, telomeres, telomerase.