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CHAPTER 18-20 PACKET OF IMMENSE JOY
1. Summarize the flow of genetic information during replication of an RNA virus. Indicate
the enzymes that catalyze this flow.
________________ ---- ________________ ---- _________________
Enzymes _______________
_______________
2. What do oncogenes code for?
3. a. What type of phage and reproductive cycle would most likely cause generalized
transduction?
b. What type of phage would cause specialized transduction?
4. a. Repressible enzymes usually function in _________________ pathways. The
pathway’s end product serves as a _________________ to activate the repressor and turn
off enzyme synthesis and prevent overproduction of the end product of the pathway.
Genes for repressible enzymes are usually switched _______________ and the repressor
is synthesized in an _________________ form.
b. Inducible enzymes usually function in _________________ pathways. Nutrient
molecules serve as _______________ to stimulate production of the enzymes necessary
for their breakdown. Genes for inducible enzymes are usually switched
___________________ and the repressor is synthesized in an _____________ form.
5. a. List the multiple levels of packing in a metaphase chromosome in order of increasing
complexity.
b. Give an example of heterochromatin common in mammalian cells.
6. Name the two human genetic diseases that have been linked to elongations of base triplet
repeats.
7. Complete the following five key points that summarize the control of gene expression in
eukaryotes.
a. Different cell types of a multicellular organism. ________________________
b. Physical state or organization of the genome makes certain genes.
_________________________
c. ________________________ may occur at each step from gene to functional
protein.
d. Control of transcription is especially important. The ____________________
activates transcription of specific genes.
e. Some of these DNA-binding proteins are responsive to ___________________.
8. What accounts for the huge variety and specificity of immunoglobulins?
9. Fill in the following table to help you organize the major mechanisms that can regulate
the expression of eukaryotic genes.
Level of Control
Examples
Gene availability (physical and a.
chemical changes)
Transcriptional control
b.
Posttranscriptional control
c.
Translational control
d.
Posttranslational control
e.
10. a. What are proto-oncogenes? How do they become oncogenes?
b. What is the role of tumor-suppressor genes in the development of cancer?
11. a. Which of these DNA sequences would function best as a recognition sequence for a
restriction enzyme? Why?
--CAGCAG---GTGCTG---GAATTC—
--GTCGTC--
--CACGAC--
b. List the four most common vectors for recombinant
c. Why do bacteria make excellent hosts for genetic engineering?
--CTTAAG—
12. What steps can be taken to facilitate the expression of a eukaryotic gene in bacteria?
13. List the four components of the Human Genome Project.
a.
b.
c.
d.
14. a. Why is it easier to perform a test for Huntington’s disease now that the gene has been
cloned?
b. What are some of the practical and ethical considerations in human gene therapy?
15. An antisense gene has been used to retard spoilage in tomatoes. Explain how this gene
would work.
16. Fill in this table on the basic tools of gene manipulation used in DNA technology.
Technique or Tool
Brief Description
Some Uses in DNA
Technology
Restriction enzymes
a.
Gel electrophoresis
b.
cDNA
c.
Labeled probe and
autoradiography
d.
Southern hybridization
e.
DNA sequencing, Sanger
method
f.
Polymerase chain reaction
(PCR)
g.
RFLP analysis
h.