ANSWERS TO REVIEW QUESTIONS
CHAPTER 19
1. BRAC1, human insulin gene, human growth hormone gene
2. Patents block research.
3. a. Restriction enzymes cut DNA at specific sequences. They can be used to create DNA
b.
c.
d.
fragments for constructing recombinant DNA molecules.
Cloning vectors carry DNA sequences into cells.
DNA microarrays are used to evaluate patterns of gene expression.
Short nucleic acids serve as probes (DNA) or to silence gene expression (RNAi and
microRNAs)
4. Antibiotics are generally used to set up a system where only cells that have taken up foreign
DNA can survive.
5. Human insulin DNA cut with a restriction enzyme, vector DNA cut with the same restriction
enzyme, E. coli , DNA ligase, selection mechanism (such as antibiotic)
6. Bacteria could not manufacture the products of human genes if the genetic code was not
universal.
7. A drug obtained using recombinant DNA technology does not contain contaminants found in
proteins extracted from organisms and it is not allergenic.
8. Foreign DNA can be inserted on a virus, carried across cell membranes in liposomes,
microinjected, electroporated, or sent in with particle bombardment.
9. Bioremediation uses an organism’s enzymes to detoxify pollutants.
10. Examining the whole exome will reveal new genes associated with the disease and genetic
relationships shared with other diseases.
11. Expose bacteria to a pollutant and those that survive have a reproductive advantage in its
presence.
12. A knockdown or gene silencing technology can be used to treat a cancer caused by an
oncogene, which is overactive by definition.
ANSWERS TO APPLIED QUESTIONS
1. The gene for the E coli enzyme is cut with a restriction enzyme, isolated and introduced into a
fertilized pig egg via microinjection or other technique. The embryo is transferred to a
surrogate and develops. Animals with phenotypes indicating they harbor cells with the E coli
gene are bred to each other to yield homozygous transgenic pigs.
2. 20 cycles x 2 minutes/cycle = 40 minutes.
3. PCR can directly detect HIV RNA, rather than a sign that the human body is responding to
the presence of the virus.
4. (1) A goat produces human EPO in its milk.
(2) A mouse produces jellyfish GFP in its blood plasma.
(3) A chicken produces human clotting factor in its egg whites.
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5. Human collagen produced in transgenic mice is less likely to include infectious agents than
collagen obtained from hooves and hides. It is also the human version of the protein, which is
less likely to stimulate an immune response than the cow type.
6. Answers vary with student opinion. Example: Perhaps people do not object to genetic
modification of bacteria because bacteria are not easily visible and the drug is used to treat
an illness.
7. Mice can express human genes because they use the same genetic code.
8. Other genes might be involved that the researcher does not include.
9. Compare gene expression profiles for men and women before and after film watching.
ANSWERS TO WEB ACTIVITIES
1.
a. Kary Mullis invented PCR to harness the power of and direct DNA replication to massproduce selected genes.
b. RNAi technology uses short synthetic RNA molecules to squelch gene expression.
c. Gene targeting through homologous recombination swaps in pieces of DNA into their
location in the genome.
d. Isolate the gene for green fluorescent protein from jellyfish and link it to other genes of
interest, to mark their encoded proteins.
2.
Examples: Humulin® for diabetes, Procrit® used to treat anemia and Actimmune® for
infection.
3.
If companies must pay licensing fees for every DNA sequence they use in a test, they
could not afford to offer the test.
4.
5.
The Human Genome Project was completed in 2003.
a. Increased energy, quicker recovery times, fewer wrinkles, increased sexiness
b. Opinion. An example might be: Yes, due to the serious nature of the side effects.
ANSWERS TO CASE STUDIES AND RESEARCH RESULTS
1. Give a ewe hormones to make her superovulate. Apply ram sperm to ewe’s reproductive tract.
Flush out fertilized ova, and inject them with human AAT gene linked to sheep gene promoter that
will control its expression. Place GM fertilized ova into sheep surrogate mothers. Select
heterozygous offspring, breed them to obtain homozygotes. Milk female homozygotes and extract
human drug.
2.
a.
b.
c.
d.
e.
Yellow fluorescence
Red fluorescence
Blank or no signal on chip
Screen before and after samples
Compare normal and sunburnt skin using DNA micrarray
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