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AP Biology
Reading Guide – Chapter 13
Chapter 13 – Biotechnology
The following websites offer wonderful tutorials and animations on these techniques, if you would like to
explore more about a technique or topic.
http://www.dnaftb.org/dnaftb/1/concept/
http://www.dnalc.org/ddnalc/resources/animations.html
http://www.hhmi.org/biointeractive/vlabs/index.html
(I especially recommend the bacterial identification lab module!!)
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OBJECTIVES
 Describe the natural function of restriction enzyme.
 Describe how restriction enzymes and gel electrophoresis are used to isolate DNA fragments.
 Explain how RFLP analysis and PCR can be applied to the diagnosing genetic disorders and
forensics.
 Explain how advances in recombinant DNA technology have helped scientists study the
eukaryotic genome.
 Describe how restriction enzymes and gel electrophoresis are used to isolate DNA fragments.
 Explain how the creation of sticky ends by restriction enzymes is useful in producing a
recombinant DNA molecule.
 Outline the procedures for producing plasmid vectors.
 Explain how cloning vectors are used in recombinant DNA technology.
 List and describe the two major sources of genes for cloning.
 Describe the function of reverse transcriptase in retroviruses and explain how they are useful in
recombinant DNA technology.
 Explain the importance of DNA synthesis and sequencing to modern studies of eukaryotic
genomes.
 Describe how bacteria can be induced to produce eukaryotic gene products.
 List and describe four complementary approaches used to map the human genome.
 Describe how recombinant DNA technology can have medical applications such as diagnosis of
genetic disease, development of gene therapy, vaccine production, and development of
pharmaceutical products.
 Describe how gene manipulation has practical applications for agriculture.
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SUMMARY
 DNA Cloning – Producing Recombinant DNA
o DNA technology makes it possible to clone genes for basic research and commercial
applications
o Restriction enzymes are used to make recombinant DNA
o Genes can be cloned in recombinant DNA vectors
o Cloned genes are stored in DNA libraries
o PCR can be used to clone a single gene or an entire genome

Detecting a Particular DNA Sequence
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AP Biology
Reading Guide – Chapter 13
o
o
o
Restriction fragment analysis detects DNA differences that affect restriction sites
RFLP analysis is the application of RE site differences
PCR can be used to identify if a particular DNA sequence is present or conduct
haplotype analysis (determine someone’s genotype)
o Southern blotting uses a small, complementary DNA sequence as a probe to detect the
presence of a particular DNA sequence and examine differences in DNA sequence
between individuals
o DNA sequencing allows for the determination of the primary DNA sequence
o A combination of these techniques can be used to map entire genomes and identify
genetic disorders
 Practical Applications of DNA Technology
o DNA technology is reshaping medicine and the pharmaceutical industry
o DNA technology offers forensic, environmental, and agricultural applications
o DNA technology raises important safety and ethical questions
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13.1 – RECOMBINANT DNA
1.
What is recombinant DNA?
2.
What are restriction enzymes? How do restriction enzymes recognize a restriction site?
3.
What is the normal purpose of restriction enzymes in bacteria?
prevent the restriction enzymes from digesting its own DNA?
4.
How does the bacterium
What is a palindrome? Why is this term used in relation to restriction enzymes?
5.
How can restriction enzymes be used to create a physical map of a DNA molecule? (Try
Question 3 on p.248 – Understand Concept)
AGAROSE GEL ELECTROPHORESIS.
6.
Which electrode do DNA fragments migrate towards (the anode or cathode)? Why?
7.
In what order to DNA fragments separate by gel electrophoresis?
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AP Biology
Reading Guide – Chapter 13
8.
What type of information can be obtained from DNA electrophoresis?
RFLP ANALYSIS (SEE P. 247, APPLY THE CONCEPT)
9.
What is DNA fingerprinting (also called RFLP analysis)? What is the basis for RFLP analysis?
10.
Describe how RFLPs and gel electrophoresis can be used to diagnose a genetic mutation such
as sickle cell anemia (fig 15.20).
13.2 - CONSTRUCTING RECOMBINANT DNA.
11.
What is the purpose of DNA cloning?
12.
How could you specifically select for only those bacterial cells that successfully incorporated the
recombinant plasmid?
13.
Describe the process involved in inserting genes from one kind of organism into cells of another
kind of organism. Be sure to describe how the vector, REs and DNA ligase are all involved.
14.
What characteristics should a vector exhibit?
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AP Biology
Reading Guide – Chapter 13
15.
Why are plasmids the most common vector used in recombinant DNA?
16.
How can we be sure the recombinant plasmid taken in by the bacteria actually contains the
gene we inserted? (hint: reporter gene)
13.3 – SOURCES OF DNA FRAGMENTS FOR CLONING
17.
What is the DNA sequence lacking introns called?
18.
How might you produce a DNA gene sequence from a human (or any eukaryote) that lacks
introns?
13.4 – APPLICATIONS OF BIOTECHNOLOGY
19.
What is an expression vector? What must an expression vector contain?
20.
List some examples of biotechnology products produced using
a) Transgenic bacteria
b) Transgenic plants
c) Transgenic animals
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AP Biology
Reading Guide – Chapter 13
21.
Summarize the ethical and other objections that have been raised against recombinant DNA
studies, and give practical and research applications of recombinant DNA.
Below are two free response questions taken from actual AP Biology exams. While I may not ask you
to submit these for grading – I am expecting you to work through these problems. If you understand
and can complete these questions, you are well on your way to understand the material from this
chapter.
1. The human genome illustrates both continuity and change.
a. Describe the essential features of each of the procedures/techniques below. For each of the
procedures/techniques, explain how its application contributes to understanding genetics.



The use of a bacterial plasmid to clone and sequence a human gene
Polymerase chain reaction
Restriction fragment length polymorphism analysis
b. All humans are nearly identical genetically in coding sequences and have many proteins that are
identical in structure and function. Nevertheless, each human has a unique DNA fingerprint. Explain
this apparent contradiction.
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AP Biology
Reading Guide – Chapter 13
2. The diagram below shows a segment of DNA with a total length of 4,900 base pairs. The arrows
indicate reaction sites for two restriction enzymes (enzyme X and enzyme Y).
Enzyme
X
DNA Segment
Length (bas e pairs)
400
500
Enzyme
Y
Enzyme
Enzyme
X
1,200
X
1,300
1,500
(A) Explain how the principles of gel electrophoresis allow for the separation of DNA fragments.
(B) Describe the results you would expect from electrophoretic separation of fragments from the
following treatments of the DNA segment above. Assume that the digestion occurred under
appropriate conditions and went to completion.
I. DNA digested with only enzyme X
II. DNA digested with only enzyme Y
III. DNA digested with enzyme X and enzyme Y combined
IV. Undigested DNA
(C) Explain both of the following:
(1). The mechanism of action of restriction enzymes
(2). The different results you would expect if a mutation occurred at the recognition
site for enzyme Y.
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