Chapter 12 DNA Technology.

Chapter 12 DNA Technology

Biology and Society: DNA, Guilt, and Innocence
DNA profiling is the analysis of DNA samples that can be used to determine whether the samples come from the same individual. DNA profiling can therefore be used in courts to indicate if someone is guilty of a crime. DNA technology has led to other advances in the creation of genetically modified crops and identification and treatment of genetic diseases. © 2013 Pearson Education, Inc. 2

RECOMBINANT DNA TECHNOLOGY
Biotechnology is the manipulation of organisms or their components to make useful products and has been used for thousands of years to make bread using yeast and selectively breed livestock for desired traits. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 3

Biotechnology today means the use of DNA technology, techniques for studying and manipulating genetic material, modifying specific genes, and moving genes between organisms. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 4

Recombinant DNA is constructed when scientists combine pieces of DNA from two different sources to form a single DNA molecule. Recombinant DNA technology is widely used in genetic engineering, the direct manipulation of genes for practical purposes. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 5

Applications: From Humulin to Foods to “Pharm” Animals
By transferring the gene for a desired protein into a bacterium or yeast, proteins that are naturally present in only small amounts can be produced in large quantities. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 6

Making Humulin In 1982, the world’s first genetically engineered pharmaceutical product was sold. Humulin, human insulin was produced by genetically modified bacteria and is used today by more than 4 million people with diabetes. Today, humulin is continuously produced in gigantic fermentation vats filled with a liquid culture of bacteria. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 7

Figure 12.3 Figure 12.3 A factory that produces genetically engineered insulin

Making Humulin DNA technology is used to produce medically valuable molecules, including human growth hormone (HGH), the hormone erythropoietin (EPO), which stimulates production of red blood cells, and vaccines, harmless variants or derivatives of a pathogen used to prevent infectious diseases. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 9

Genetically Modified (GM) Foods
Today, DNA technology is quickly replacing traditional breeding programs. Scientists have produced many types of genetically modified (GM) organisms, organisms that have acquired one or more genes by artificial means. A transgenic organism contains a gene from another organism, typically of another species. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 10

In the United States today, roughly half of the corn crop and more than three-quarters of the soybean and cotton crops are genetically modified. Corn has been genetically modified to resist insect infestation, attack by an insect called the European corn borer. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 11

Figure 12.4 Figure 12.4 Genetically modified corn

Strawberry plants produce bacterial proteins that act as a natural antifreeze, protecting the plants from cold weather. Potatoes and rice have been modified to produce harmless proteins derived from the cholera bacterium and may one day serve as edible vaccines. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 13

“Golden rice 2” is a transgenic variety of rice that carries genes from daffodils and corn and could help prevent vitamin A deficiency and resulting blindness. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 14

Figure 12.5 Figure 12.5 Genetically modified rice

“Pharm” Animals A transgenic pig has been produced that carries a gene for human hemoglobin, which can be isolated and used in human blood transfusions. In 2006, genetically modified pigs carried roundworm genes that produce proteins that convert less healthy fatty acids to omega-3 fatty acids. However, unlike transgenic plants, no transgenic animals are yet sold as food. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 16

Figure 12.6 Figure 12.6 A genetically modified swine

Recombinant DNA Techniques
Bacteria are the workhorses of modern biotechnology. To work with genes in the laboratory, biologists often use bacterial plasmids, small, circular DNA molecules that replicate separately from the larger bacterial chromosome. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 18

Plasmids Bacterial chromosome Remnant of bacterium Colorized TEM
Figure 12.7 Plasmids Bacterial chromosome Colorized TEM Remnant of bacterium Figure 12.7 Bacterial plasmids

Recombinant DNA Techniques
Plasmids can carry virtually any gene, can act as vectors, DNA carriers that move genes from one cell to another, and are ideal for gene cloning, the production of multiple identical copies of a gene-carrying piece of DNA. Recombinant DNA techniques can help biologists produce large quantities of a desired protein. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 20

Figure 12.8 Bacterial cell 1 2 Isolate plasmids. Isolate DNA. Cell containing the gene of interest Plasmid 3 Cut both DNAs with same enzyme. DNA DNA fragments from cell Gene of interest Other genes 4 Mix the DNA fragments and join them together. Gene of interest Recombinant DNA plasmids 5 Bacteria take up recombinant plasmids. Recombinant bacteria Bacterial clone 6 Clone the bacteria. 7 Find the clone with the gene of interest. A gene for pest resistance is inserted into plants. A protein is used to dissolve blood clots in heart attack therapy. Some uses of genes Some uses of proteins 8 The gene and protein of interest are isolated from the bacteria. A gene is used to alter bacteria for cleaning up toxic waste. Genes may be inserted into other organisms. Bacteria produce proteins, which can be harvested and used directly. A protein is used to prepare “stone-washed” blue jeans. Figure 12.8 Using recombinant DNA technology to produce useful products

Cell containing the gene of interest
Figure 12.8a Bacterial cell Cell containing the gene of interest Plasmid DNA 2 1 Isolate DNA. Isolate plasmids. 3 Cut both DNAs with same enzyme. DNA fragments from cell Gene of interest Other genes 4 Mix the DNA fragments and join them together. Gene of interest Recombinant DNA plasmids Figure 12.8 Using recombinant DNA technology to produce useful products (part 1)

Bacteria take up recombinant plasmids.
Figure 12.8b 5 Bacteria take up recombinant plasmids. Recombinant bacteria Bacterial clone 6 Clone the bacteria. 7 Find the clone with the gene of interest. Figure 12.8 Using recombinant DNA technology to produce useful products (part 2)

Some uses of genes Some uses of proteins 8
Figure 12.8c Some uses of genes Some uses of proteins 8 The gene and protein of interest are isolated from the bacteria. Genes may be inserted into other organisms. Harvested proteins may be used directly. Genes for cleaning up toxic waste Protein for “stone-washing” jeans Gene for pest resistance Protein for dissolving clots Figure 12.8 Using recombinant DNA technology to produce useful products (part 3)

A Closer Look: Cutting and Pasting DNA with Restriction Enzymes
Recombinant DNA is produced by combining two ingredients: a bacterial plasmid and the gene of interest. To combine these ingredients, a piece of DNA must be spliced into a plasmid. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 25

A Closer Look: Cutting and Pasting DNA with Restriction Enzymes
This splicing process can be accomplished by using restriction enzymes, which cut DNA at specific nucleotide sequences (restriction sites), and producing pieces of DNA called restriction fragments with “sticky ends” important for joining DNA from different sources. DNA ligase connects the DNA pieces into continuous strands by forming bonds between adjacent nucleotides. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 26

Recognition site (recognition sequence) for a restriction enzyme DNA
Figure Recognition site (recognition sequence) for a restriction enzyme DNA 1 A restriction enzyme cuts the DNA into fragments. Restriction enzyme Sticky end Sticky end Figure 12.9 Cutting and pasting DNA (step 1)

Figure Recognition site (recognition sequence) for a restriction enzyme DNA 1 A restriction enzyme cuts the DNA into fragments. Restriction enzyme Sticky end Sticky end 2 A DNA fragment is added from another source. Figure 12.9 Cutting and pasting DNA (step 2)

Figure Recognition site (recognition sequence) for a restriction enzyme DNA 1 A restriction enzyme cuts the DNA into fragments. Restriction enzyme Sticky end Sticky end 2 A DNA fragment is added from another source. 3 Fragments stick together by base pairing. Figure 12.9 Cutting and pasting DNA (step 3)

Figure Recognition site (recognition sequence) for a restriction enzyme DNA 1 A restriction enzyme cuts the DNA into fragments. Restriction enzyme Sticky end Sticky end 2 A DNA fragment is added from another source. 3 Fragments stick together by base pairing. 4 DNA ligase joins the fragments into strands. DNA ligase Recombinant DNA molecule Figure 12.9 Cutting and pasting DNA (step 4)

A Closer Look: Obtaining the Gene of Interest
How can a researcher obtain DNA that encodes a particular gene of interest? A “shotgun” approach can yield millions of recombinant plasmids carrying many different segments of foreign DNA. A collection of cloned DNA fragments that includes an organism’s entire genome (a complete set of its genes) is called a genomic library. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 31

Once a genomic library is created, the bacterial clone containing the desired gene is identified using a nucleic acid probe consisting of a short single strand of DNA with a complementary sequence and labeled with either a radioactive isotope or a fluorescent dye. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 32

(single-stranded DNA)
Figure 12.10 Radioactive probe (single-stranded DNA) Mix with single-stranded DNA from various bacterial clones Single-stranded DNA Base pairing indicates the gene of interest Figure How a DNA probe tags a gene

Another way to obtain a gene of interest is to use reverse transcriptase and synthesize the gene by using an mRNA template. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 34

Introns removed and exons spliced together
Figure 12.11 Cell nucleus Exon Intron Exon Intron Exon DNA of eukaryotic gene 1 Transcription RNA transcript 2 Introns removed and exons spliced together mRNA Test tube 3 Isolation of mRNA from cell and addition of reverse transcriptase Reverse transcriptase 4 Synthesis of cDNA strand cDNA strand being synthesized 5 Synthesis of second DNA strand by DNA polymerase cDNA of gene without introns Figure Making a gene from eukaryotic mRNA

Introns removed and exons spliced together
Figure 12.11a Cell nucleus Exon Intron Exon Intron Exon DNA of eukaryotic gene 1 Transcription RNA transcript 2 Introns removed and exons spliced together mRNA Test tube 3 Isolation of mRNA from cell and addition of reverse transcriptase Figure Making a gene from eukaryotic mRNA (part 1)

Isolation of mRNA from cell and addition of
Figure 12.11b Test tube 3 Isolation of mRNA from cell and addition of reverse transcriptase Reverse transcriptase 4 Synthesis of cDNA strand cDNA strand being synthesized 5 Synthesis of second DNA strand by DNA polymerase cDNA of gene without introns Figure Making a gene from eukaryotic mRNA (part 2)

Another approach is to use an automated DNA-synthesizing machine and synthesize a gene of interest from scratch. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Student comprehension of restriction enzymes, nucleic acid probes, and many other aspects of recombinant DNA techniques depend upon a comfortable understanding of basic molecular genetics. Consider addressing Chapter 12 after an exam that addresses the content in Chapters 10 and 11. 2. Students might bring some awareness and/or concerns about biotechnology to the classroom, for example, in their reactions to the controversies regarding genetically modified (GM) foods. This experience can be used to generate class interest and to highlight the importance of good information when making judgments. Consider starting class with a headline addressing one of these issues. The recent process of FDA approval for genetically engineered salmon raised for food might be particularly useful and relevant. Teaching Tips 1. Annual flu vaccinations are a common example of using vaccines to prevent diseases that cannot be easily cured. However, students might not understand why many people receive the vaccine every year. A new annual vaccine is necessary because the flu viruses keep evolving. 2. Genetically engineered organisms are controversial, creating various degrees and directions of social resistance; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of this or related issues. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 3. The origin of the name “restriction enzymes” may be of interest. In nature, these enzymes protect bacterial cells against foreign DNA. Thus, these enzymes “restrict” the invasion of foreign genetic material. 4. The ability to swap genes between prokaryotes and eukaryotes using the technologies described in this chapter reveal the fundamental genetic mechanisms shared by all forms of life. This very strong evidence of common descent is a lesson about evolution that may be missed by your students. 5. Students might think you are just making a bad joke by noting that laboratory synthesized genes are “designer genes,” but this is a common term. Search the Internet using the keywords “designer genes,” and many scientific (and unscientific) sites will be found. 6. A genomic library of the sentence you are now reading would be all of the sentence fragments that make up the sentence. One could string together all of the words of this first sentence, without spaces between letters, and then conduct a word-processing edit placing a space between any place where an “e” is followed by the letter “n.” The resulting fragments of this original sentence would look like this, and would be similar to a type of “genomic library.” Age nomic library of these nte nce you are now reading would be all of these nte nce fragments that made up these nte nce. 7. Some Internet search programs rely on a methodology similar in one way to the use of a nucleic acid probe. For example, if you want to find the lyrics to a particular song, but you do not know the song title or artist, you might search the Internet using a unique phrase from the song. (For example, search using “yellow submarine.”) The search engine will scan millions of web pages to identify those sites containing that particular phrase. However, unlike a nucleic acid probe, you would search for the song by using a few of the lyrics. A nucleic acid probe would search using a sequence complementary to the desired sequence. 8. Roundup Ready Corn, a product of Monsanto, is resistant to the herbicide Roundup. The general strategy for farmers is to spray fields of Roundup Ready Corn with the herbicide Roundup, killing weeds but not the corn. A search of the Internet will quickly reveal the controversy associated with this and other genetically modified organisms (GMOs), which can encourage interesting discussions and promote critical thinking skills. 9. As gene therapy technology expands, our ability to modify the genome in human embryos, created through in vitro fertilization, permits genetic modification at the earliest stages of life. Future generations of humans, like our crops today, may include those with and without a genetically modified ancestry. The benefits and challenges of these technologies raise issues many students have never considered. Our students, and the generations soon to follow, will face the potential of directed human evolution. 38

DNA PROFILING AND FORENSIC SCIENCE
can be used to determine if two samples of genetic material are from a particular individual and has rapidly revolutionized the field of forensics, the scientific analysis of evidence from crime scenes. To produce a DNA profile, scientists compare sequences in the genome that vary from person to person. Video: Biotechnology Lab © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Television programs might lead some students to expect that DNA profiling is quick and easy. Ask students to consider why DNA profiling actually takes many days or weeks to complete. 2. Students might expect DNA profiling for criminal investigations to involve an analysis of the entire human genome. Consider explaining why such an analysis is unrealistic and unnecessary. 3. The many forms of DNA technology discussed in this chapter provide powerful evidence of evolution. Although not addressed regularly in this chapter, consider reminding students that these techniques continue to reinforce and inform our understandings of the common descent of life on Earth. Teaching Tips 1. In most legal cases, the probability of two people having identical DNA profiles can be one in 10 billion or more. However, eyewitness testimony has been a standard part of the justice system. If you want to make the point about the unreliability of eyewitnesses in a trial, compared to techniques such as genetic profiling, consider this exercise. Arrange for a person who is not well known to the class to run into your classroom, take something you have placed near you (perhaps a bag, stack of papers, box), and leave quickly. You need to take care that no one in the class is so alarmed as to do something dangerous. Once the “thief” is gone, tell the class that this was planned but not to speak. Have them each write a description of the person, including height, hair color, clothing, facial hair, behavior, and so on. Many students will be accurate, but some will likely get details wrong. This is also an effective exercise to demonstrate the need for large sample sizes and accurate recording devices for good scientific technique. 2. Although the statistical odds of a DNA-profiling match can exceed one in 10 billion, the odds of a mistake in the collecting and testing procedures can be much greater. This is an important distinction. An error as simple as mislabeling a sample can confuse the results. Unfortunately, the odds of human error will vary and are difficult to determine. 3. In PCR, the product becomes another master copy. Imagine that while you are photocopying, every copy is used as a master at another copy machine. (This would require many copy machines.) 4. Students might need a little more practice understanding the products of restriction enzymes. Consider these two words, equilibrium and equalibrium. Imagine that a mutation produced the spelling error of the second word. If we used a “restriction enzyme” that splits these words between “u” and “i,” how will the fragments compare in size and number? equilibrium = equ ilibri um (three fragments of three, six, and two letters) equalibrium = equalibri um (two fragments of nine and two letters) 5. Separating marker ink using paper chromatography is a simple experiment that approximates some of what occurs in gel electrophoresis. Consider doing this as a class demonstration while addressing electrophoresis. Cut a large piece of filter paper into a rectangle or square. Use markers to color large dots about 2 cm away from the edge of the paper. Separate the dots from each other by 3–4 cm. Place the paper on edge, dots down, into a beaker containing about 1 cm of ethanol or isopropyl alcohol (50% or higher will do). The dots should not be in contact with the pool of alcohol in the bottom of the beaker. As the alcohol is drawn up the filter paper by capillary action, the alcohol will dissolve the ink dots. As the alcohol continues up the paper, the ink follows. Not all of the ink components move at the same speed, based on their size and chemical properties. If you begin the process at the start of class, you should have some degree of separation by the end of a 50-minute period. Experiment with the technique a day or two before class to fine-tune the demonstration, and experiment with different types of ink. (Save and air-dry these samples for your class.) Consider using brown, green, and black markers, as these colors are often made by color combinations. 39

1 DNA isolated Crime scene Suspect 1 Suspect 2 Figure 12.13-1
Figure Overview of DNA profiling (step 1)

1 DNA isolated 2 DNA amplified Crime scene Suspect 1 Suspect 2
Figure Crime scene Suspect 1 Suspect 2 1 DNA isolated 2 DNA amplified Figure Overview of DNA profiling (step 2)

1 DNA isolated 2 DNA amplified 3 DNA compared Crime scene Suspect 1
Figure Crime scene Suspect 1 Suspect 2 1 DNA isolated 2 DNA amplified 3 DNA compared Figure Overview of DNA profiling (step 3)

Investigating Murder, Paternity, and Ancient DNA
DNA profiling can be used to test the guilt of suspected criminals, identify tissue samples of victims, resolve paternity cases, identify contraband animal products, and trace the evolutionary history of organisms. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Television programs might lead some students to expect that DNA profiling is quick and easy. Ask students to consider why DNA profiling actually takes many days or weeks to complete. 2. Students might expect DNA profiling for criminal investigations to involve an analysis of the entire human genome. Consider explaining why such an analysis is unrealistic and unnecessary. 3. The many forms of DNA technology discussed in this chapter provide powerful evidence of evolution. Although not addressed regularly in this chapter, consider reminding students that these techniques continue to reinforce and inform our understandings of the common descent of life on Earth. Teaching Tips 1. In most legal cases, the probability of two people having identical DNA profiles can be one in 10 billion or more. However, eyewitness testimony has been a standard part of the justice system. If you want to make the point about the unreliability of eyewitnesses in a trial, compared to techniques such as genetic profiling, consider this exercise. Arrange for a person who is not well known to the class to run into your classroom, take something you have placed near you (perhaps a bag, stack of papers, box), and leave quickly. You need to take care that no one in the class is so alarmed as to do something dangerous. Once the “thief” is gone, tell the class that this was planned but not to speak. Have them each write a description of the person, including height, hair color, clothing, facial hair, behavior, and so on. Many students will be accurate, but some will likely get details wrong. This is also an effective exercise to demonstrate the need for large sample sizes and accurate recording devices for good scientific technique. 2. Although the statistical odds of a DNA-profiling match can exceed one in 10 billion, the odds of a mistake in the collecting and testing procedures can be much greater. This is an important distinction. An error as simple as mislabeling a sample can confuse the results. Unfortunately, the odds of human error will vary and are difficult to determine. 3. In PCR, the product becomes another master copy. Imagine that while you are photocopying, every copy is used as a master at another copy machine. (This would require many copy machines.) 4. Students might need a little more practice understanding the products of restriction enzymes. Consider these two words, equilibrium and equalibrium. Imagine that a mutation produced the spelling error of the second word. If we used a “restriction enzyme” that splits these words between “u” and “i,” how will the fragments compare in size and number? equilibrium = equ ilibri um (three fragments of three, six, and two letters) equalibrium = equalibri um (two fragments of nine and two letters) 5. Separating marker ink using paper chromatography is a simple experiment that approximates some of what occurs in gel electrophoresis. Consider doing this as a class demonstration while addressing electrophoresis. Cut a large piece of filter paper into a rectangle or square. Use markers to color large dots about 2 cm away from the edge of the paper. Separate the dots from each other by 3–4 cm. Place the paper on edge, dots down, into a beaker containing about 1 cm of ethanol or isopropyl alcohol (50% or higher will do). The dots should not be in contact with the pool of alcohol in the bottom of the beaker. As the alcohol is drawn up the filter paper by capillary action, the alcohol will dissolve the ink dots. As the alcohol continues up the paper, the ink follows. Not all of the ink components move at the same speed, based on their size and chemical properties. If you begin the process at the start of class, you should have some degree of separation by the end of a 50-minute period. Experiment with the technique a day or two before class to fine-tune the demonstration, and experiment with different types of ink. (Save and air-dry these samples for your class.) Consider using brown, green, and black markers, as these colors are often made by color combinations. 43

Figure 12.14 Figure Cheddar Man

DNA Profiling Techniques The Polymerase Chain Reaction (PCR)
is a technique to copy quickly and precisely a specific segment of DNA and can generate enough DNA, from even minute amounts of blood or other tissue, to allow DNA profiling. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Television programs might lead some students to expect that DNA profiling is quick and easy. Ask students to consider why DNA profiling actually takes many days or weeks to complete. 2. Students might expect DNA profiling for criminal investigations to involve an analysis of the entire human genome. Consider explaining why such an analysis is unrealistic and unnecessary. 3. The many forms of DNA technology discussed in this chapter provide powerful evidence of evolution. Although not addressed regularly in this chapter, consider reminding students that these techniques continue to reinforce and inform our understandings of the common descent of life on Earth. Teaching Tips 1. In most legal cases, the probability of two people having identical DNA profiles can be one in 10 billion or more. However, eyewitness testimony has been a standard part of the justice system. If you want to make the point about the unreliability of eyewitnesses in a trial, compared to techniques such as genetic profiling, consider this exercise. Arrange for a person who is not well known to the class to run into your classroom, take something you have placed near you (perhaps a bag, stack of papers, box), and leave quickly. You need to take care that no one in the class is so alarmed as to do something dangerous. Once the “thief” is gone, tell the class that this was planned but not to speak. Have them each write a description of the person, including height, hair color, clothing, facial hair, behavior, and so on. Many students will be accurate, but some will likely get details wrong. This is also an effective exercise to demonstrate the need for large sample sizes and accurate recording devices for good scientific technique. 2. Although the statistical odds of a DNA-profiling match can exceed one in 10 billion, the odds of a mistake in the collecting and testing procedures can be much greater. This is an important distinction. An error as simple as mislabeling a sample can confuse the results. Unfortunately, the odds of human error will vary and are difficult to determine. 3. In PCR, the product becomes another master copy. Imagine that while you are photocopying, every copy is used as a master at another copy machine. (This would require many copy machines.) 4. Students might need a little more practice understanding the products of restriction enzymes. Consider these two words, equilibrium and equalibrium. Imagine that a mutation produced the spelling error of the second word. If we used a “restriction enzyme” that splits these words between “u” and “i,” how will the fragments compare in size and number? equilibrium = equ ilibri um (three fragments of three, six, and two letters) equalibrium = equalibri um (two fragments of nine and two letters) 5. Separating marker ink using paper chromatography is a simple experiment that approximates some of what occurs in gel electrophoresis. Consider doing this as a class demonstration while addressing electrophoresis. Cut a large piece of filter paper into a rectangle or square. Use markers to color large dots about 2 cm away from the edge of the paper. Separate the dots from each other by 3–4 cm. Place the paper on edge, dots down, into a beaker containing about 1 cm of ethanol or isopropyl alcohol (50% or higher will do). The dots should not be in contact with the pool of alcohol in the bottom of the beaker. As the alcohol is drawn up the filter paper by capillary action, the alcohol will dissolve the ink dots. As the alcohol continues up the paper, the ink follows. Not all of the ink components move at the same speed, based on their size and chemical properties. If you begin the process at the start of class, you should have some degree of separation by the end of a 50-minute period. Experiment with the technique a day or two before class to fine-tune the demonstration, and experiment with different types of ink. (Save and air-dry these samples for your class.) Consider using brown, green, and black markers, as these colors are often made by color combinations. 45

Number of DNA molecules
Figure 12.15 Initial DNA segment 1 2 4 8 Number of DNA molecules Figure DNA amplification by PCR

Short Tandem Repeat (STR) Analysis
How do you test if two samples of DNA come from the same person? Repetitive DNA makes up much of the DNA that lies between genes in humans and consists of nucleotide sequences that are present in multiple copies in the genome. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Television programs might lead some students to expect that DNA profiling is quick and easy. Ask students to consider why DNA profiling actually takes many days or weeks to complete. 2. Students might expect DNA profiling for criminal investigations to involve an analysis of the entire human genome. Consider explaining why such an analysis is unrealistic and unnecessary. 3. The many forms of DNA technology discussed in this chapter provide powerful evidence of evolution. Although not addressed regularly in this chapter, consider reminding students that these techniques continue to reinforce and inform our understandings of the common descent of life on Earth. Teaching Tips 1. In most legal cases, the probability of two people having identical DNA profiles can be one in 10 billion or more. However, eyewitness testimony has been a standard part of the justice system. If you want to make the point about the unreliability of eyewitnesses in a trial, compared to techniques such as genetic profiling, consider this exercise. Arrange for a person who is not well known to the class to run into your classroom, take something you have placed near you (perhaps a bag, stack of papers, box), and leave quickly. You need to take care that no one in the class is so alarmed as to do something dangerous. Once the “thief” is gone, tell the class that this was planned but not to speak. Have them each write a description of the person, including height, hair color, clothing, facial hair, behavior, and so on. Many students will be accurate, but some will likely get details wrong. This is also an effective exercise to demonstrate the need for large sample sizes and accurate recording devices for good scientific technique. 2. Although the statistical odds of a DNA-profiling match can exceed one in 10 billion, the odds of a mistake in the collecting and testing procedures can be much greater. This is an important distinction. An error as simple as mislabeling a sample can confuse the results. Unfortunately, the odds of human error will vary and are difficult to determine. 3. In PCR, the product becomes another master copy. Imagine that while you are photocopying, every copy is used as a master at another copy machine. (This would require many copy machines.) 4. Students might need a little more practice understanding the products of restriction enzymes. Consider these two words, equilibrium and equalibrium. Imagine that a mutation produced the spelling error of the second word. If we used a “restriction enzyme” that splits these words between “u” and “i,” how will the fragments compare in size and number? equilibrium = equ ilibri um (three fragments of three, six, and two letters) equalibrium = equalibri um (two fragments of nine and two letters) 5. Separating marker ink using paper chromatography is a simple experiment that approximates some of what occurs in gel electrophoresis. Consider doing this as a class demonstration while addressing electrophoresis. Cut a large piece of filter paper into a rectangle or square. Use markers to color large dots about 2 cm away from the edge of the paper. Separate the dots from each other by 3–4 cm. Place the paper on edge, dots down, into a beaker containing about 1 cm of ethanol or isopropyl alcohol (50% or higher will do). The dots should not be in contact with the pool of alcohol in the bottom of the beaker. As the alcohol is drawn up the filter paper by capillary action, the alcohol will dissolve the ink dots. As the alcohol continues up the paper, the ink follows. Not all of the ink components move at the same speed, based on their size and chemical properties. If you begin the process at the start of class, you should have some degree of separation by the end of a 50-minute period. Experiment with the technique a day or two before class to fine-tune the demonstration, and experiment with different types of ink. (Save and air-dry these samples for your class.) Consider using brown, green, and black markers, as these colors are often made by color combinations. 47

Blast Animation: DNA Fingerprinting
Short Tandem Repeat (STR) Analysis Short tandem repeats (STRs) are short sequences of DNA and repeated many times, tandemly (one after another), in the genome. STR analysis is a method of DNA profiling and compares the lengths of STR sequences at specific sites in the genome. Blast Animation: DNA Fingerprinting © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Television programs might lead some students to expect that DNA profiling is quick and easy. Ask students to consider why DNA profiling actually takes many days or weeks to complete. 2. Students might expect DNA profiling for criminal investigations to involve an analysis of the entire human genome. Consider explaining why such an analysis is unrealistic and unnecessary. 3. The many forms of DNA technology discussed in this chapter provide powerful evidence of evolution. Although not addressed regularly in this chapter, consider reminding students that these techniques continue to reinforce and inform our understandings of the common descent of life on Earth. Teaching Tips 1. In most legal cases, the probability of two people having identical DNA profiles can be one in 10 billion or more. However, eyewitness testimony has been a standard part of the justice system. If you want to make the point about the unreliability of eyewitnesses in a trial, compared to techniques such as genetic profiling, consider this exercise. Arrange for a person who is not well known to the class to run into your classroom, take something you have placed near you (perhaps a bag, stack of papers, box), and leave quickly. You need to take care that no one in the class is so alarmed as to do something dangerous. Once the “thief” is gone, tell the class that this was planned but not to speak. Have them each write a description of the person, including height, hair color, clothing, facial hair, behavior, and so on. Many students will be accurate, but some will likely get details wrong. This is also an effective exercise to demonstrate the need for large sample sizes and accurate recording devices for good scientific technique. 2. Although the statistical odds of a DNA-profiling match can exceed one in 10 billion, the odds of a mistake in the collecting and testing procedures can be much greater. This is an important distinction. An error as simple as mislabeling a sample can confuse the results. Unfortunately, the odds of human error will vary and are difficult to determine. 3. In PCR, the product becomes another master copy. Imagine that while you are photocopying, every copy is used as a master at another copy machine. (This would require many copy machines.) 4. Students might need a little more practice understanding the products of restriction enzymes. Consider these two words, equilibrium and equalibrium. Imagine that a mutation produced the spelling error of the second word. If we used a “restriction enzyme” that splits these words between “u” and “i,” how will the fragments compare in size and number? equilibrium = equ ilibri um (three fragments of three, six, and two letters) equalibrium = equalibri um (two fragments of nine and two letters) 5. Separating marker ink using paper chromatography is a simple experiment that approximates some of what occurs in gel electrophoresis. Consider doing this as a class demonstration while addressing electrophoresis. Cut a large piece of filter paper into a rectangle or square. Use markers to color large dots about 2 cm away from the edge of the paper. Separate the dots from each other by 3–4 cm. Place the paper on edge, dots down, into a beaker containing about 1 cm of ethanol or isopropyl alcohol (50% or higher will do). The dots should not be in contact with the pool of alcohol in the bottom of the beaker. As the alcohol is drawn up the filter paper by capillary action, the alcohol will dissolve the ink dots. As the alcohol continues up the paper, the ink follows. Not all of the ink components move at the same speed, based on their size and chemical properties. If you begin the process at the start of class, you should have some degree of separation by the end of a 50-minute period. Experiment with the technique a day or two before class to fine-tune the demonstration, and experiment with different types of ink. (Save and air-dry these samples for your class.) Consider using brown, green, and black markers, as these colors are often made by color combinations. 48

Crime scene DNA STR site 1 STR site 2 AGAT GATA Same number of
Figure 12.16 Crime scene DNA STR site 1 STR site 2 AGAT GATA Same number of short tandem repeats Different numbers of short tandem repeats AGAT GATA Suspect’s DNA Figure Short tandem repeat (STR) sites

Blast Animation: Gel Electrophoresis
STR analysis compares the lengths of DNA fragments and uses gel electrophoresis, a method for sorting macromolecules—usually proteins or nucleic acids—primarily by their electrical charge and size. Blast Animation: Gel Electrophoresis © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Television programs might lead some students to expect that DNA profiling is quick and easy. Ask students to consider why DNA profiling actually takes many days or weeks to complete. 2. Students might expect DNA profiling for criminal investigations to involve an analysis of the entire human genome. Consider explaining why such an analysis is unrealistic and unnecessary. 3. The many forms of DNA technology discussed in this chapter provide powerful evidence of evolution. Although not addressed regularly in this chapter, consider reminding students that these techniques continue to reinforce and inform our understandings of the common descent of life on Earth. Teaching Tips 1. In most legal cases, the probability of two people having identical DNA profiles can be one in 10 billion or more. However, eyewitness testimony has been a standard part of the justice system. If you want to make the point about the unreliability of eyewitnesses in a trial, compared to techniques such as genetic profiling, consider this exercise. Arrange for a person who is not well known to the class to run into your classroom, take something you have placed near you (perhaps a bag, stack of papers, box), and leave quickly. You need to take care that no one in the class is so alarmed as to do something dangerous. Once the “thief” is gone, tell the class that this was planned but not to speak. Have them each write a description of the person, including height, hair color, clothing, facial hair, behavior, and so on. Many students will be accurate, but some will likely get details wrong. This is also an effective exercise to demonstrate the need for large sample sizes and accurate recording devices for good scientific technique. 2. Although the statistical odds of a DNA-profiling match can exceed one in 10 billion, the odds of a mistake in the collecting and testing procedures can be much greater. This is an important distinction. An error as simple as mislabeling a sample can confuse the results. Unfortunately, the odds of human error will vary and are difficult to determine. 3. In PCR, the product becomes another master copy. Imagine that while you are photocopying, every copy is used as a master at another copy machine. (This would require many copy machines.) 4. Students might need a little more practice understanding the products of restriction enzymes. Consider these two words, equilibrium and equalibrium. Imagine that a mutation produced the spelling error of the second word. If we used a “restriction enzyme” that splits these words between “u” and “i,” how will the fragments compare in size and number? equilibrium = equ ilibri um (three fragments of three, six, and two letters) equalibrium = equalibri um (two fragments of nine and two letters) 5. Separating marker ink using paper chromatography is a simple experiment that approximates some of what occurs in gel electrophoresis. Consider doing this as a class demonstration while addressing electrophoresis. Cut a large piece of filter paper into a rectangle or square. Use markers to color large dots about 2 cm away from the edge of the paper. Separate the dots from each other by 3–4 cm. Place the paper on edge, dots down, into a beaker containing about 1 cm of ethanol or isopropyl alcohol (50% or higher will do). The dots should not be in contact with the pool of alcohol in the bottom of the beaker. As the alcohol is drawn up the filter paper by capillary action, the alcohol will dissolve the ink dots. As the alcohol continues up the paper, the ink follows. Not all of the ink components move at the same speed, based on their size and chemical properties. If you begin the process at the start of class, you should have some degree of separation by the end of a 50-minute period. Experiment with the technique a day or two before class to fine-tune the demonstration, and experiment with different types of ink. (Save and air-dry these samples for your class.) Consider using brown, green, and black markers, as these colors are often made by color combinations. 50

Mixture of DNA fragments of different sizes
Figure Mixture of DNA fragments of different sizes Power source Figure Gel electrophoresis of DNA molecules (step 1)

Figure Mixture of DNA fragments of different sizes Power source Figure Gel electrophoresis of DNA molecules (step 2)

Figure Mixture of DNA fragments of different sizes Band of longest (slowest) fragments Power source Band of shortest (fastest) fragments Figure Gel electrophoresis of DNA molecules (step 3)

The DNA fragments are visualized as “bands” on the gel.
Gel Electrophoresis The DNA fragments are visualized as “bands” on the gel. The differences in the locations of the bands reflect the different lengths of the DNA fragments. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Television programs might lead some students to expect that DNA profiling is quick and easy. Ask students to consider why DNA profiling actually takes many days or weeks to complete. 2. Students might expect DNA profiling for criminal investigations to involve an analysis of the entire human genome. Consider explaining why such an analysis is unrealistic and unnecessary. 3. The many forms of DNA technology discussed in this chapter provide powerful evidence of evolution. Although not addressed regularly in this chapter, consider reminding students that these techniques continue to reinforce and inform our understandings of the common descent of life on Earth. Teaching Tips 1. In most legal cases, the probability of two people having identical DNA profiles can be one in 10 billion or more. However, eyewitness testimony has been a standard part of the justice system. If you want to make the point about the unreliability of eyewitnesses in a trial, compared to techniques such as genetic profiling, consider this exercise. Arrange for a person who is not well known to the class to run into your classroom, take something you have placed near you (perhaps a bag, stack of papers, box), and leave quickly. You need to take care that no one in the class is so alarmed as to do something dangerous. Once the “thief” is gone, tell the class that this was planned but not to speak. Have them each write a description of the person, including height, hair color, clothing, facial hair, behavior, and so on. Many students will be accurate, but some will likely get details wrong. This is also an effective exercise to demonstrate the need for large sample sizes and accurate recording devices for good scientific technique. 2. Although the statistical odds of a DNA-profiling match can exceed one in 10 billion, the odds of a mistake in the collecting and testing procedures can be much greater. This is an important distinction. An error as simple as mislabeling a sample can confuse the results. Unfortunately, the odds of human error will vary and are difficult to determine. 3. In PCR, the product becomes another master copy. Imagine that while you are photocopying, every copy is used as a master at another copy machine. (This would require many copy machines.) 4. Students might need a little more practice understanding the products of restriction enzymes. Consider these two words, equilibrium and equalibrium. Imagine that a mutation produced the spelling error of the second word. If we used a “restriction enzyme” that splits these words between “u” and “i,” how will the fragments compare in size and number? equilibrium = equ ilibri um (three fragments of three, six, and two letters) equalibrium = equalibri um (two fragments of nine and two letters) 5. Separating marker ink using paper chromatography is a simple experiment that approximates some of what occurs in gel electrophoresis. Consider doing this as a class demonstration while addressing electrophoresis. Cut a large piece of filter paper into a rectangle or square. Use markers to color large dots about 2 cm away from the edge of the paper. Separate the dots from each other by 3–4 cm. Place the paper on edge, dots down, into a beaker containing about 1 cm of ethanol or isopropyl alcohol (50% or higher will do). The dots should not be in contact with the pool of alcohol in the bottom of the beaker. As the alcohol is drawn up the filter paper by capillary action, the alcohol will dissolve the ink dots. As the alcohol continues up the paper, the ink follows. Not all of the ink components move at the same speed, based on their size and chemical properties. If you begin the process at the start of class, you should have some degree of separation by the end of a 50-minute period. Experiment with the technique a day or two before class to fine-tune the demonstration, and experiment with different types of ink. (Save and air-dry these samples for your class.) Consider using brown, green, and black markers, as these colors are often made by color combinations. 54

Amplified Amplified crime scene suspect’s DNA DNA Longer fragments
Figure 12.18 Amplified crime scene DNA Amplified suspect’s DNA Longer fragments Shorter fragments Figure Visualizing STR fragment patterns

RFLP Analysis Gel electrophoresis may also be used for RFLP analysis, in which DNA molecules are exposed to a restriction enzyme, producing fragments that are compared and made visible by gel electrophoresis. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Television programs might lead some students to expect that DNA profiling is quick and easy. Ask students to consider why DNA profiling actually takes many days or weeks to complete. 2. Students might expect DNA profiling for criminal investigations to involve an analysis of the entire human genome. Consider explaining why such an analysis is unrealistic and unnecessary. 3. The many forms of DNA technology discussed in this chapter provide powerful evidence of evolution. Although not addressed regularly in this chapter, consider reminding students that these techniques continue to reinforce and inform our understandings of the common descent of life on Earth. Teaching Tips 1. In most legal cases, the probability of two people having identical DNA profiles can be one in 10 billion or more. However, eyewitness testimony has been a standard part of the justice system. If you want to make the point about the unreliability of eyewitnesses in a trial, compared to techniques such as genetic profiling, consider this exercise. Arrange for a person who is not well known to the class to run into your classroom, take something you have placed near you (perhaps a bag, stack of papers, box), and leave quickly. You need to take care that no one in the class is so alarmed as to do something dangerous. Once the “thief” is gone, tell the class that this was planned but not to speak. Have them each write a description of the person, including height, hair color, clothing, facial hair, behavior, and so on. Many students will be accurate, but some will likely get details wrong. This is also an effective exercise to demonstrate the need for large sample sizes and accurate recording devices for good scientific technique. 2. Although the statistical odds of a DNA-profiling match can exceed one in 10 billion, the odds of a mistake in the collecting and testing procedures can be much greater. This is an important distinction. An error as simple as mislabeling a sample can confuse the results. Unfortunately, the odds of human error will vary and are difficult to determine. 3. In PCR, the product becomes another master copy. Imagine that while you are photocopying, every copy is used as a master at another copy machine. (This would require many copy machines.) 4. Students might need a little more practice understanding the products of restriction enzymes. Consider these two words, equilibrium and equalibrium. Imagine that a mutation produced the spelling error of the second word. If we used a “restriction enzyme” that splits these words between “u” and “i,” how will the fragments compare in size and number? equilibrium = equ ilibri um (three fragments of three, six, and two letters) equalibrium = equalibri um (two fragments of nine and two letters) 5. Separating marker ink using paper chromatography is a simple experiment that approximates some of what occurs in gel electrophoresis. Consider doing this as a class demonstration while addressing electrophoresis. Cut a large piece of filter paper into a rectangle or square. Use markers to color large dots about 2 cm away from the edge of the paper. Separate the dots from each other by 3–4 cm. Place the paper on edge, dots down, into a beaker containing about 1 cm of ethanol or isopropyl alcohol (50% or higher will do). The dots should not be in contact with the pool of alcohol in the bottom of the beaker. As the alcohol is drawn up the filter paper by capillary action, the alcohol will dissolve the ink dots. As the alcohol continues up the paper, the ink follows. Not all of the ink components move at the same speed, based on their size and chemical properties. If you begin the process at the start of class, you should have some degree of separation by the end of a 50-minute period. Experiment with the technique a day or two before class to fine-tune the demonstration, and experiment with different types of ink. (Save and air-dry these samples for your class.) Consider using brown, green, and black markers, as these colors are often made by color combinations. 56

Restriction enzymes added
Figure 12.19 Crime scene DNA Suspect’s DNA Fragment w Cut Fragment z Restriction enzymes added Fragment x Cut Cut Fragment y Fragment y Crime scene DNA Suspect’s DNA Longer fragments z x w y y Shorter fragments Figure RFLP analysis

Restriction enzymes added
Figure 12.19a Crime scene DNA Suspect’s DNA Fragment w Cut Fragment z Restriction enzymes added Fragment x Cut Cut Fragment y Fragment y Figure RFLP analysis (part 1)

Crime scene DNA Suspect’s DNA
Figure 12.19b Crime scene DNA Suspect’s DNA Longer fragments z x w y y Shorter fragments Figure RFLP analysis (part 2)

GENOMICS AND PROTEOMICS
Genomics is the study of complete sets of genes (genomes). The first targets of genomics research were bacteria. As of 2011, the genomes of more than 1,700 species have been published and more than 8,000 are in progress. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 60

Table 12.1 Table 12.1 Some important sequenced genomes

Table 12.1a Table 12.1 Some important sequenced genomes (part 1)

Table 12.1b Table 12.1 Some important sequenced genomes (part 2)

The Human Genome Project
Begun in 1990, the Human Genome Project was a massive scientific endeavor to determine the nucleotide sequence of all the DNA in the human genome and identify the location and sequence of every gene. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 64

At the completion of the project, more than 99% of the genome had been determined to % accuracy, about 3 billion nucleotide pairs were identified, about 21,000 genes were found, and about 98% of the human DNA was identified as noncoding. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 65

The Human Genome Project can help map the genes for specific diseases such as Alzheimer’s disease and Parkinson’s disease. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 66

Tracking the Anthrax Killer
In October 2001, a Florida man died after inhaling anthrax and by the end of the year, four other people had also died from anthrax. In 2008, investigators completed a whole-genome analysis of the spores used in the attack, found four unique mutations, and traced the mutations to a single flask at an Army facility. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 67

Envelope containing anthrax spores Anthrax spore Colorized SEM
Figure 12.21 Envelope containing anthrax spores Anthrax spore Colorized SEM Figure The 2001 anthrax attacks

Although never charged, an army research scientist suspected in the case committed suicide in 2008, and the case remains officially unsolved. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 69

The anthrax investigation is just one example of the new field of bioinformatics, the application of computational tools to molecular biology. Additional examples include evidence that a Florida dentist transmitted HIV to several patients, tracing the West Nile virus outbreak in 1999 to a single natural strain of virus infecting birds and people, and determining that our closest living relative, the chimpanzee (Pan troglodytes), shares 96% of our genome. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 70

Genome-Mapping Techniques
Genomes are most often sequenced using the whole-genome shotgun method, in which the entire genome is chopped into fragments using restriction enzymes, all the fragments are cloned and sequenced, and computers running specialized mapping software reassemble the millions of overlapping short sequences into a single continuous sequence for every chromosome—an entire genome. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 71

Figure Chromosome Figure Genome sequencing (step 1)

Chromosome Chop up with restriction enzyme DNA fragments
Figure Chromosome Chop up with restriction enzyme DNA fragments Figure Genome sequencing (step 2)

Figure Chromosome Chop up with restriction enzyme DNA fragments Sequence fragments Figure Genome sequencing (step 3)

Figure Chromosome Chop up with restriction enzyme DNA fragments Sequence fragments Align fragments Figure Genome sequencing (step 4)

Figure Chromosome Chop up with restriction enzyme DNA fragments Sequence fragments Align fragments Reassemble full sequence Figure Genome sequencing (step 5)

Figure 12.22a Figure Genome sequencing (photo)

The Process of Science: Can Genomics Cure Cancer?
Observation: A few patients responded quite dramatically to a new drug, gefitinib, which targets a protein called EGFR found on the surface of cells that line the lungs and is used to treat lung cancer. Question: Are genetic differences among lung cancer patients responsible for the differences in gefitinib’s effectiveness? © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 78

Figure 12.23 Figure The EGFR protein: Fighting cancer with genomics

Proteomics Success in genomics has given rise to proteomics, the systematic study of the full set of proteins found in organisms. To understand the functioning of cells and organisms, scientists are studying when and where proteins are produced and how they interact. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. The text notes that there are 24 chromosomes in the human genome. Students might initially find this confusing, as it is common knowledge that humans have 23 pairs of chromosomes. Consider making the statement that we have 24 different types of chromosomes and asking your students to explain why this is true. 2. The similarities of the genotypes and phenotypes of members of a human family tree are expected and understood by most students. Yet, for many students, these same relationships are often poorly extrapolated to phylogenetic relationships of other groups. The use of genomics to test phylogenetic relationships is an enormously powerful tool used in modern systematics. Genomics is a significant test of the other overwhelming types of evidence for evolution. Teaching Tips 1. The first targets of genomics were prokaryotic pathogenic organisms. Consider asking your students in class to suggest why this was a good choice. Students may note that the genomes of these organisms are smaller than eukaryotes and that many of these organisms are of great medical significance. 2. The authors note that there are about 3 billion nucleotide pairs in the human genome. There are about 3 billion seconds in about 95 years. This simple reference might add meaning to the significance of these large numbers. 3. The main U.S. Department of Energy Office website in support of the Human Genome Project is found at 4. The website for the National Center for Biotechnology Information is The center, established in 1988, serves as a national resource for biomedical information related to genomic data. 5. Challenge students to explain why a complete understanding of an organism’s genome and the resulting proteins produced is still not enough to understand the full biology of an organism. Challenge them to consider the role of the environment in development and physiology. (One striking example of the influence of the environment is that the sex of some reptiles is determined not by genetics, but by incubation temperature!) 6. With a better understanding of the diverse and still unknown roles of many sections of DNA, consider discussing some of the difficulties of “resurrecting” extinct organisms from incomplete DNA sequences. 80

HUMAN GENE THERAPY Human gene therapy is a recombinant DNA procedure,
seeks to treat disease by altering the genes of the afflicted person, and often replaces or supplements the mutant version of a gene with a properly functioning one. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Using gene therapy to “fix” genetic problems relies on a thorough understanding of the roles of genes and alleles. Students might benefit from a discussion of the extent to which we as a society might want to consider directing our own genetics. Teaching Tips 1. Ethical, legal, and social issues related to the Human Genome Project are directly addressed at the Department of Energy Human Genome website at 2. The Biology and Society end-of-chapter textbook questions address some of the issues raised in this chapter section. 81

Bone marrow cells of the patient are infected with the virus.
Figure 12.24 Normal human gene 1 An RNA version of a normal human gene is inserted into a harmless RNA virus. RNA genome of virus Inserted human RNA Healthy person 2 Bone marrow cells of the patient are infected with the virus. 3 Viral DNA carrying the human gene inserts into the cell’s chromosome. Bone marrow cell from the patient Bone marrow Bone of person with disease 4 The engineered cells are injected into the patient. Figure One approach to human gene therapy

Figure 12.24a Normal human gene 1 An RNA version of a normal human gene is inserted into a harmless RNA virus. RNA genome of virus Inserted human RNA Healthy person Figure One approach to human gene therapy (part 1)

Bone marrow cells of the patient are infected with the virus.
Figure 12.24b 2 Bone marrow cells of the patient are infected with the virus. 3 Viral DNA carrying the human gene inserts into the cell’s chromosome. Bone marrow cell from the patient Bone marrow Bone of person with disease 4 The engineered cells are injected into the patient. Figure One approach to human gene therapy (part 2)

HUMAN GENE THERAPY Severe combined immunodeficiency (SCID) is
a fatal inherited disease and caused by a single defective gene that prevents the development of the immune system. SCID patients quickly die unless treated with a bone marrow transplant or gene therapy. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Using gene therapy to “fix” genetic problems relies on a thorough understanding of the roles of genes and alleles. Students might benefit from a discussion of the extent to which we as a society might want to consider directing our own genetics. Teaching Tips 1. Ethical, legal, and social issues related to the Human Genome Project are directly addressed at the Department of Energy Human Genome website at 2. The Biology and Society end-of-chapter textbook questions address some of the issues raised in this chapter section. 85

HUMAN GENE THERAPY From 2000 to 2011, gene therapy has cured 22 children with inborn SCID. However, there have been some serious side effects. Four of the children developed leukemia, which proved fatal to one. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1. Using gene therapy to “fix” genetic problems relies on a thorough understanding of the roles of genes and alleles. Students might benefit from a discussion of the extent to which we as a society might want to consider directing our own genetics. Teaching Tips 1. Ethical, legal, and social issues related to the Human Genome Project are directly addressed at the Department of Energy Human Genome website at 2. The Biology and Society end-of-chapter textbook questions address some of the issues raised in this chapter section. 86

SAFETY AND ETHICAL ISSUES
As soon as scientists realized the power of DNA technology, they began to worry about potential dangers such as the creation of hazardous new pathogens and transfer of cancer genes into infectious bacteria and viruses. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1.The many issues raised in this chapter are of great potential significance and remain unresolved. An informed debate about rights, responsibilities, and possibilities continues regarding these scientific issues. 2. The Genetic Information Nondiscrimination Act was passed in May Details about this important legislation can be found at Teaching Tips 1. Genetically engineered organisms are controversial, creating various degrees of concern; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of genetic engineering. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 2. Consider a person who opposes GM food by stating “I do not want any DNA in my food.” You might want to have your students respond to this person’s concerns. 87

SAFETY AND ETHICAL ISSUES
Strict laboratory safety procedures have been designed to protect researchers from infection by engineered microbes and prevent microbes from accidentally leaving the laboratory. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1.The many issues raised in this chapter are of great potential significance and remain unresolved. An informed debate about rights, responsibilities, and possibilities continues regarding these scientific issues. 2. The Genetic Information Nondiscrimination Act was passed in May Details about this important legislation can be found at Teaching Tips 1. Genetically engineered organisms are controversial, creating various degrees of concern; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of genetic engineering. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 2. Consider a person who opposes GM food by stating “I do not want any DNA in my food.” You might want to have your students respond to this person’s concerns. 88

The Controversy over Genetically Modified Foods
GM strains account for a significant percentage of several staple crops in the United States. Advocates of a cautious approach are concerned that crops carrying genes from other species might harm the environment, GM foods could be hazardous to human health, and/or transgenic plants might pass their genes to close relatives in nearby wild areas. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1.The many issues raised in this chapter are of great potential significance and remain unresolved. An informed debate about rights, responsibilities, and possibilities continues regarding these scientific issues. 2. The Genetic Information Nondiscrimination Act was passed in May Details about this important legislation can be found at Teaching Tips 1. Genetically engineered organisms are controversial, creating various degrees of concern; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of genetic engineering. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 2. Consider a person who opposes GM food by stating “I do not want any DNA in my food.” You might want to have your students respond to this person’s concerns. 89

Negotiators from 130 countries (including the United States) agreed on a Biosafety Protocol that requires exporters to identify GM organisms present in bulk food shipments and allows importing countries to decide whether the shipments pose environmental or health risks. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1.The many issues raised in this chapter are of great potential significance and remain unresolved. An informed debate about rights, responsibilities, and possibilities continues regarding these scientific issues. 2. The Genetic Information Nondiscrimination Act was passed in May Details about this important legislation can be found at Teaching Tips 1. Genetically engineered organisms are controversial, creating various degrees of concern; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of genetic engineering. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 2. Consider a person who opposes GM food by stating “I do not want any DNA in my food.” You might want to have your students respond to this person’s concerns. 90

In the United States, all projects are evaluated for potential risks by a number of regulatory agencies, including the Food and Drug Administration, Environmental Protection Agency, National Institutes of Health, and Department of Agriculture. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1.The many issues raised in this chapter are of great potential significance and remain unresolved. An informed debate about rights, responsibilities, and possibilities continues regarding these scientific issues. 2. The Genetic Information Nondiscrimination Act was passed in May Details about this important legislation can be found at Teaching Tips 1. Genetically engineered organisms are controversial, creating various degrees of concern; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of genetic engineering. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 2. Consider a person who opposes GM food by stating “I do not want any DNA in my food.” You might want to have your students respond to this person’s concerns. 91

Ethical Questions Raised by DNA Technology
DNA technology raises legal and ethical questions—few of which have clear answers. Should genetically engineered human growth hormone be used to stimulate growth in HGH-deficient children? Should we try to eliminate genetic defects in our children and their descendants? Should people use mail-in kits that can tell healthy people their relative risk of developing various diseases? © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1.The many issues raised in this chapter are of great potential significance and remain unresolved. An informed debate about rights, responsibilities, and possibilities continues regarding these scientific issues. 2. The Genetic Information Nondiscrimination Act was passed in May Details about this important legislation can be found at Teaching Tips 1. Genetically engineered organisms are controversial, creating various degrees of concern; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of genetic engineering. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 2. Consider a person who opposes GM food by stating “I do not want any DNA in my food.” You might want to have your students respond to this person’s concerns. 92

Ethical Questions Raised by DNA Technology
DNA technologies raise many complex issues that have no easy answers. We as a society and as individuals must become educated about DNA technologies to address the ethical questions raised by their use. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1.The many issues raised in this chapter are of great potential significance and remain unresolved. An informed debate about rights, responsibilities, and possibilities continues regarding these scientific issues. 2. The Genetic Information Nondiscrimination Act was passed in May Details about this important legislation can be found at Teaching Tips 1. Genetically engineered organisms are controversial, creating various degrees of concern; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of genetic engineering. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 2. Consider a person who opposes GM food by stating “I do not want any DNA in my food.” You might want to have your students respond to this person’s concerns. 93

Evolution Connection: The Y Chromosome as a Window on History
Barring mutations, the human Y chromosome passes essentially intact from father to son. By comparing Y DNA, researchers can learn about the ancestry of human males. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1.The many issues raised in this chapter are of great potential significance and remain unresolved. An informed debate about rights, responsibilities, and possibilities continues regarding these scientific issues. 2. The Genetic Information Nondiscrimination Act was passed in May Details about this important legislation can be found at Teaching Tips 1. Genetically engineered organisms are controversial, creating various degrees of concern; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of genetic engineering. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 2. Consider a person who opposes GM food by stating “I do not want any DNA in my food.” You might want to have your students respond to this person’s concerns. 94

Evolution Connection: The Y Chromosome as a Window on History
DNA profiling of the Y chromosome has revealed that nearly 16 million men currently living may be descended from Genghis Khan, nearly 10% of Irish men were descendants of Niall of the Nine Hostages, a warlord who lived during the 1400s, and the Lemba people of southern Africa are descended from ancient Jews. © 2013 Pearson Education, Inc. Student Misconceptions and Concerns 1.The many issues raised in this chapter are of great potential significance and remain unresolved. An informed debate about rights, responsibilities, and possibilities continues regarding these scientific issues. 2. The Genetic Information Nondiscrimination Act was passed in May Details about this important legislation can be found at Teaching Tips 1. Genetically engineered organisms are controversial, creating various degrees of concern; yet many debates around issues of science are confused by misinformation. This may be an opportunity for you to make an extra credit or regular assignment for students to take a position, on one side or the other, on some aspect of genetic engineering. The science would need to be accurate. Students might debate whether a food product made from GM/transgenic organisms should be labeled as such, or students can discuss the risks or advantages of producing GM organisms. 2. Consider a person who opposes GM food by stating “I do not want any DNA in my food.” You might want to have your students respond to this person’s concerns. 95

DNA isolated from two sources and cut by same
Figure 12.UN01 DNA isolated from two sources and cut by same restriction enzyme Gene of interest (could be obtained from a library or synthesized) Plasmid (vector) Recombinant DNA Transgenic organisms Useful products Figure 12.UN01 Summary of Key Concepts: Recombinant DNA Techniques

DNA fragments compared by gel electrophoresis
Figure 12.UN02 Crime scene Suspect 1 Suspect 2 DNA Polymerase chain reaction (PCR) amplifies STR sites Longer DNA fragments Gel Shorter DNA fragments DNA fragments compared by gel electrophoresis (Bands of shorter fragments move faster toward the positive pole.) Figure 12.UN02 Summary of Key Concepts: DNA Profiling Techniques

A normal human gene is transcribed
Figure 12.UN03 RNA version of a normal human gene Virus with RNA genome Bone marrow A normal human gene is transcribed and translated in a patient, potentially curing the genetic disease permanently Figure 12.UN03 Summary of Key Concepts: Human Gene Therapy

Chapter 12 DNA Technology.

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