Download HANDOUT: CH 16 pt 2 Study

WLHS / AP Bio / Monson
Name
Date
Per.
CH 16 STUDY QUESTIONS, part 2: DNA Replication and Repair
1) Describe the SEMICONSERVATIVE model of DNA replication.
2) What is the source of energy that drives the polymerization of DNA?
3) What is meant by “antiparallel”?
4) In what “direction” does DNA synthesis occur? Why?
5) Distinguish between the LEADING and LAGGING strands in DNA replication.
6) What are Okazaki fragments?  Where and why do they form?
7) What is a PRIMER? Why is it necessary in DNA replication?
8) Briefly explain the function of each protein / enzyme listed below:
A) Helicase
B) Single stranded binding protein
C) Topoisomerase
D) Primase
E) DNA Polymerases
F) DNA Ligase
9) List at least 4 factors or agents which can cause damage to DNA.
10) What is mismatch repair? If this mechanism does not work properly, what happens to the cell over time?
11) Describe the DNA repair mechanism known as excision repair, including ALL of the enzymes involved.
12) What are telomeres? What is the advantage of having telomeres?
13) What is the role of telomerase? In which cells is telomerase present and active, and in which cells is it absent?
What is the significance of this???
14) Nerve cells do not replicate their DNA after reaching maturity. A cell biologist observed that there was x
amount of DNA in a human nerve cell. In four other types of human cells, labeled A-D, she measured the following
amounts of DNA: cell A, 2x; cell B, 1.6x; cell C, 0.5x; cell D, x
Match the four cell types with the following choices: (1) sperm cell; (2) bone cell just beginning interphase; (3) skin
cell in the S phase; (4) intestinal cell beginning mitosis. (Hint: review the phases of the cell cycle and mitosis in
chapter 12 if needed!).
15) Label this diagram with as much detail as possible. (HINT: see Figure 16.17 in text)