Version A. AP* Biology: Biotechnology. Name: Period

Transcription

1 Name: Period Version A AP* Biology: Biotechnology Directions: Each of the questions or incomplete statements below is followed by four suggested answers or completions. Select the one that is best in each case and enter the appropriate letter in the corresponding space on the answer sheet. 1. The enzyme that is found in retroviruses and that is required for the synthesis of DNA from viral RNA is A) DNA polymerase III B) RNA polymerase C) restriction endonuclease D) reverse transcriptase 2. Which of the following statements about plasmids is correct? A) They are found only in eukaryotic cells. B) They are synthesized in the endoplasmic reticulum. C) They are self-replicating. D) They are composed of RNA. 3. The use of the isotope 32 P as a tracer element in the study of invasion and lysis of bacteria by viruses has shown that A) ATP from bacteriophages is identical to ATP found in eukaryotic cells B) bacteriophage protein enters the bacteria through the cell wall C) bacteriophage nucleic acids enter bacteria prior to lysis D) 32 P accelerates the lytic effect of bacteriophage infection 4. Which of the following best describes why the polymerase chain reaction is a standard technique used in molecular biology research? A) It uses inexpensive materials and produces perfect results. B) It can purify specific sections of a DNA molecule. C) It can produce large amounts of specific DNA sequences. D) It can duplicate the entire human genome. 5. A tobacco plant can be made to express a gene from fireflies, resulting in the emission of light. Which of the following is the basis for this phenomenon? A) Chloroplasts can be made to produce light if firefly proteins are injected into plant cells. B) Fireflies and tobacco plants share a recent common ancestor. C) Fireflies and tobacco plants are infected by the same kinds of bacteria. D) Transcription and translation are fundamentally similar in both fireflies and tobacco plants. 6. The process in which a bacterial cell picks up extraneous DNA from the environment is called A) transformation B) translation C) transcription D) transduction (1)Test Questions are Copyright by College Entrance Examination Board, Prenceton, NJ. All rights reserved. For face-to-fact teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is registered traemark of the College Entrance Examination Borard. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permissionis granted of individual classroom teahcers to reproduce the activity sheets and illustation for their own classroom use. Any other type of reproduction of these material is strictly prohibited. 1

2 Version A 7. A genetic engineer prepares DNA fragments from two species and mixes them together. Two of the many fragments are shown below. Which of the following statements is correct? A) No sticky ends were produced. B) The two fragments shown above will join by complementary base pairing. C) The two fragments were prepared by two different restriction endonucleases. D) A single restriction endonuclease was used to cut at different location in the two types of DNA 8. Which of the following explanations describes how RNA viruses increase genetic variation? A) They have higher quantities of plasmids which increase the genetic diversity of the host cell. B) RNA viruses are more likely to be involved in conjugation thus transferring more genetic information to a host cell. C) RNA viruses inject larger amounts of genetic material into host cells thus causing more mutations. D) RNA viruses have higher rates of mutation due to the lack of mechanisms for detecting replication errors. Questions 9 and 10 refer to the figure below showing the two main reproductive strategies of a bacteriophage. 9. Which of the following best depicts the sequence of events for the reproduction of a virus? I) The viral mrna is then translated into protein (parts of the capsid, tail fibers, etc.). II) The virus injects itself, or its genetic material, into a host cell. III) The new virus particles burst out of the cell (lyse) and are able to go and infect other healthy cells. IV) The viral DNA is encased inside capsid proteins and all the parts are assembled to make multiple virus particles. V) The genetic material then replicates and/or is transcribed into viral mrna. A) III, IV, V, I, II B) II, V, I, IV, III C) IV, I, III, II, V D) II, V, I, III, IV 2

3 Version A 10. Which of the following is a true statement regarding the lysogenic cycle? A) Once the DNA is integrated into the host cell s genome, it immediately goes into the lytic cycle. B) The host cell is unaffected by the new genetic material that it now contains. C) It can increase the pathogenicity of the prokaryote. D) The host cell is allowed to facilitate transcription, but is unable to perform translation. Questions refer to the graph below for a population of bacteria exposed to bacteriophages. 11. The viral reproductive strategy used by the bacteriophages is A) the lytic cycle B) conjugation C) lysogenic cycle D) transformation 12. Which of the following explanations best describes why the bacterial population was able to reach carrying capacity again after the initial attack? A) The bacterial cells, after some time, are able to fight off the viral attack through phagocytosis. B) The virus particles ran out of available resources in which to obtain energy. C) The virus particles are only able to infect a certain number of bacterial cells and once those cells die, the rest are able to repopulate. D) Some bacteria either acquire resistant mutations or are innately immune to the viruses and thus survive and repopulate. 3

4 Version A 13. After some time, the bacterial and virus populations seem to reach an equilibrium. Which of the following explanations best describes a possible reason for this. A) All of the bacteria have become immune to the virus particles. B) A lysogenic situation occurs where the viral genetic material gets incorporated into the host cell genome. C) The virus particles are no longer infecting the bacterial cells. D) This is what is known as a lag phase and is the precursor to another major bacterial population decline. 14. Which of the following predictions indicates what would happen to the the bacterial population in the figure if the bacteriophages were never introduced? A) The line on the graph indicating bacterial growth would go through cycles of drastic increases in growth and sharp declines. B) The bacterial population would have continued to increase due to the absence of the predator. C) The bacterial population size would still have dropped due to depleted resources. D) The population size would have stayed relatively close to what it was when the graph indicates the virus was added. 15. HIV is a retrovirus. This is a virus whose genetic information is maintained in the form of RNA. Which of the following explains how this type of virus is able to incorporate itself into the host cell s genome? A) The viral RNA is able to incorporate itself directly into the host cell s genome. B) The viral RNA is able to be converted into viral DNA using an enzyme called reverse transcriptase. C) The host cell s DNA polymerase transcribes the viral RNA into DNA. D) The host cell s DNA ligase is able to glue DNA nucleotides onto viral RNA allowing it to attach to the host cell s genome. 4

5 Version A Questions refer to the electrophoresis gel below. An experiment was performed to separate four samples of viral DNA fragments each radioactively labeled with 32 P. The fragments were separated by gel electrophoresis. 16. Which of the following would be a possible explanation for the single band shown for Sample 3? A) The restriction enzyme being used did not make any cuts along the DNA strand. B) The electrodes could have been switched in the middle of the experiment. C) Sample 3 did not contain enough DNA polymerase to facilitate this experiment. D) Sample 3 could be recombinant DNA which does not separate correctly during this procedure. 17. The electrophoretic separation of the pieces of DNA in each of the four samples was achieved because of differential migration of the DNA fragments in an electric field. This differential migration was caused by the A) relative amounts of radioactivity in the DNA B) number of cleavage points per fragment C) size of each fragment D) overall positive charge of each fragment 18. The DNA was labeled with 32 P in order to A) visualize the fragments B) stimulate DNA replication C) inhibit the uptake of unlabeled ATP D) show which fragments included the 5 end and which fragments included the 3 end 19. A virologist creates a particular strain of virus that consists of T2 phage DNA and a T4 phage capsid. A particular bacterial population is exposed to this strain. After the lytic cycle is complete, the new bacteriophages would have A) a T2 capsid and T4 DNA. B) a T2 capsid and T2 DNA. C) a T4 capsid and T3 DNA. D) a T4 capsid and T4 DNA. 20. Which of the following about plasmids is correct? A) They are composed of RNA. B) They are larger in size than bacterial chromosomes. C) They are synthesized on the smooth endoplasmic reticulum. D) Viruses, prokaryotes, and eukaryotes can all have them. 5

6 Version A 21. The Mayinga strain of Ebola Zaire is 90% fatal in humans. In October 1989, the virus broke loose at a primate research facility in Reston, Virginia. The monkeys were from the Philippines, where they had contracted Ebola Zaire. On the plane ride from the Philippines to Virginia, the virus evolved into a new strain that was now capable of being airborne. However, much to the surprise of the scientists trying to contain the Reston outbreak, the virus was now 0% fatal in humans. The new strain was called Ebola Reston. Which of the following is a possible explanation for why this virus was able to evolve so quickly? A) This virus has a very high rate of mutation with no error-fixing mechanisms. B) This virus is able to adapt to its surroundings and change its DNA to match the phenotypes that it needs. C) Ebola is able to use reverse transcriptase to translate viral DNA into viral RNA. D) Ebola Zaire was not able to combine/recombine information as they continue to infect the same cells. 6

7 Version A Questions refer to the following scenario. A student uses restriction enzymes to cut a DNA molecule into fragments. The digested DNA is loaded into the wells of an agarose gel and the gel is subjected to an electric current. Upon completion of the run, the gel is stained. 22. The rate of migration of the DNA fragments through the agarose gel is determined by the A) ratio of adenine to cytosine in the fragment B) presence of hydrogen bonds between base pairs C) length of time the electrophoresis unit is allowed to operate D) number of nucleotides in the fragment 23. Which of the following is true of the dye used to stain the fragments? A) It increases the contrast between the agar and the DNA fragments. B) It must be accounted for when calculating the molecular weight of the fragments. C) Its charged areas interfere with the migration of the DNA. D) It is bonded only to the sticky ends of the fragments and can directly determine the sequence of the DNA fragments. 24. The type and density of the gel are important because A) they influence the rate of migration of the fragments B) they may cause some DNA molecules to replicate C) some DNA nucleotides may be lost due to chemical reactions with the gel D) some DNA molecules may sink to the bottom and not migrate 25. The procedures described can be used to do all of the following EXCEPT A) isolate and purify certain DNA fragments B) synthesize novel DNA molecules C) study the activity of restriction enzymes D) calculate the size of DNA fragments 7

8 Version A Questions refer to the following scenario. A scientist is using an ampicillin-sensitive strain of bacteria that cannot use lactose because it has a nonfunctional gene in the lac operon. She has two plasmids. One contains a functional copy of the affected gene of the lac operon, and the other contains the gene for ampicillin resistance. Using restriction enzymes and DNA ligase, she forms a recombinant plasmid containing both genes. She then adds a high concentration of the plasmid to a tube of the bacteria in a medium for bacterial growth that contains glucose as the only energy source. This tube (+) and a control tube (-) with similar bacteria but no plasmid are both incubated under the appropriate conditions for growth and plasmid uptake. The scientist then spreads a sample of each bacterial culture (+ and -) on each of the three types of plates indicated below. 26. If no new mutations occur, it would be most reasonable to expect bacterial growth on which of the following plates? A) 1 and 2 only B) 3 and 4 only C) 5 and 6 only D) 1, 2, 3, and The scientist used restriction enzymes for what purpose in the experiment? A) To make the plasmid small enough to transform cells B) To make cuts in the plasmid DNA C) To make the plasmid enter the cells D) To enable the fragments of DNA to form ionic bonds 8

9 Version A 28. If the scientist used the cultures to perform another experiment as shown above, using medium that contained lactose as the only energy source, growth would most likely occur on which of the following plates? A) 10 only B) 7 and 8 only C) 7 and 9 only D) 8 and 10 only 29. If the scientist had forgotten to use DNA ligase during the preparation of the recombinant plasmid, bacterial growth would most likely have occurred on which of the following? A) 1 and 2 only B) 1 and 4 only C) 4 and 5 only D) 1, 2, and 3 only 9

10 Version A Questions refer to the following scenario. In 1928, Fredrick Griffith performed an experiment to determine whether pathogenicity can be conferred between two different strains of a bacterium (Streptococcus pneumoniae). One strain, the S (smooth) strain was known to cause pneumonia in mice due the presence of a protein capsule. The other strain, the R (rough) strain lacked a protein capsule and did not cause the mice to die of pneumonia. Procedure I: Procedure II: Procedure III: Procedure IV: Mice were given living S cells. These mice died. Mice were given living R cells. These mice survived. Mice were given heat-killed S cells. These mice survived. Mice were given a mixture of heat-killed S cells and living R cells. These mice died. 30. A reasonable conclusion to draw from the results of the experiment is that A) the S cells incorporated a plasmid from the R cells and used it to make the outer capsule. B) the R cells built a capsule out of their own DNA. C) heat-killed S cells are no longer able to confer pathogenicity onto other cells. D) the R cells incorporated a plasmid from the heat-killed S cells and used it to produce their own capsules. 31. Which of the following explains why, at the beginning of the experiment, the living S cells were pathogenic and the living R cells were not? 32. What was Griffith s purpose for injecting mice with heat-killed S cells? A) To fix the capsule in place so that it would be able to infect the mice more efficiently. B) This served as the positive control by showing that no matter whether the S cells were heat-killed or not, they caused death to the mice. C) To demonstrate that the transforming factor is a protein. D) This served as the negative control by showing that mice injected with heat-killed S cells did not die. A) The S cells had capsules around them which served as protection against the animal s immune system. B) The R cells were slower than the S cells are were not able to outrun the white blood cells. C) The R cells lacked certain enzymes, which the S cells had. D) The S cells were the only ones carrying the disease-causing gene. 10

11 AP Biology Biotechnology Unit Exam Part B Directions: These three questions require numeric answers. Calculate the correct answer for each question, and enter your answer on the grid following each question. Examples of correct entry for the grid-in questions are shown below. The actual questions for this exam begin on the next page. Integer Answer Integer Answer Decimal Answer Fraction Answer (1) Test Questions are Copyright by College Entrance Examination Board, Princeton, NJ. All rights reserved. For face-to-face teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is a registered trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permission is granted for individual classroom teachers to reproduce the activity sheets and illustrations for their own classroom use. Any other type of reproduction of these materials is strictly prohibited.

12 Part B Directions: Part B consists of three questions requiring numeric answers. Calculate the correct answer for each question, and enter the line on the answer sheet. 1. Use the graph above to calculate the mean rate of fatality (individual deaths per year) for the eight years between 1988 and Give your answer to the nearest whole number. (1) Test Questions are Copyright by College Entrance Examination Board, Princeton, NJ. All rights reserved. For face-to-face teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is a registered trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permission is granted for individual classroom teachers to reproduce the activity sheets and illustrations for their own classroom use. Any other type of reproduction of these materials is strictly prohibited.

13 2. During a transformation experiment, a student introduces a plasmid that promotes resistance to ampicillin (common antibacterial agent) to E. coli bacterial cells. The solution containing the bacterial cells and the plasmid (0.02 µg of DNA) is spread on a plate containing Luria broth and ampicillin. The student analyzes the results 16 hours later and finds 23 colonies growing on the plate. Calculate the transformation efficiency in # colonies/µg. Give your answer to the nearest whole number. (1) Test Questions are Copyright by College Entrance Examination Board, Princeton, NJ. All rights reserved. For face-to-face teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is a registered trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permission is granted for individual classroom teachers to reproduce the activity sheets and illustrations for their own classroom use. Any other type of reproduction of these materials is strictly prohibited.

14 3. Four more students replicate the transformation experiment from question #2 and calculate their transformation efficiencies. Their results are found in the table below. Student Transformation Efficiency (colonies/µg) Calculate the standard deviation of the results. Give your answer to the nearest whole number. (1) Test Questions are Copyright by College Entrance Examination Board, Princeton, NJ. All rights reserved. For face-to-face teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is a registered trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permission is granted for individual classroom teachers to reproduce the activity sheets and illustrations for their own classroom use. Any other type of reproduction of these materials is strictly prohibited.

15 Name: Period Version B AP* Biology: Biotechnology Directions: Each of the questions or incomplete statements below is followed by four suggested answers or completions. Select the one that is best in each case and enter the appropriate letter in the corresponding space on the answer sheet. Questions 1-3 refer to the electrophoresis gel below. An experiment was performed to separate four samples of viral DNA fragments each radioactively labeled with 32 P. The fragments were separated by gel electrophoresis. 1. The DNA was labeled with 32 P in order to A) visualize the fragments B) stimulate DNA replication C) inhibit the uptake of unlabeled ATP D) show which fragments included the 5 end and which fragments included the 3 end 2. The electrophoretic separation of the pieces of DNA in each of the four samples was achieved because of differential migration of the DNA fragments in an electric field. This differential migration was caused by the A) relative amounts of radioactivity in the DNA B) number of cleavage points per fragment C) size of each fragment D) overall positive charge of each fragment (1)Test Questions are Copyright by College Entrance Examination Board, Prenceton, NJ. All rights reserved. For face-to-fact teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is registered traemark of the College Entrance Examination Borard. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permissionis granted of individual classroom teahcers to reproduce the activity sheets and illustation for their own classroom use. Any other type of reproduction of these material is strictly prohibited. 1

16 Version B 3. Which of the following would be a possible explanation for the single band shown for Sample 3? A) The restriction enzyme being used did not make any cuts along the DNA strand. B) The electrodes could have been switched in the middle of the experiment. C) Sample 3 did not contain enough DNA polymerase to facilitate this experiment. D) Sample 3 could be recombinant DNA which does not separate correctly during this procedure. Questions 4-7 refer to the following scenario. A student uses restriction enzymes to cut a DNA molecule into fragments. The digested DNA is loaded into the wells of an agarose gel and the gel is subjected to an electric current. Upon completion of the run, the gel is stained. 4. The type and density of the gel are important because A) they influence the rate of migration of the fragments B) they may cause some DNA molecules to replicate C) some DNA nucleotides may be lost due to chemical reactions with the gel D) some DNA molecules may sink to the bottom and not migrate 5. The procedures described can be used to do all of the following EXCEPT A) isolate and purify certain DNA fragments B) synthesize novel DNA molecules C) study the activity of restriction enzymes D) calculate the size of DNA fragments 6. The rate of migration of the DNA fragments through the agarose gel is determined by the A) ratio of adenine to cytosine in the fragment B) presence of hydrogen bonds between base pairs C) length of time the electrophoresis unit is allowed to operate D) number of nucleotides in the fragment 7. Which of the following is true of the dye used to stain the fragments? A) It increases the contrast between the agar and the DNA fragments. B) It must be accounted for when calculating the molecular weight of the fragments. C) Its charged areas interfere with the migration of the DNA. D) It is bonded only to the sticky ends of the fragments and can directly determine the sequence of the DNA fragments. 2

17 Version B 8. Which of the following about plasmids is correct? A) They are composed of RNA. B) They are larger in size than bacterial chromosomes. C) They are synthesized on the smooth endoplasmic reticulum. D) Viruses, prokaryotes, and eukaryotes can all have them. Questions 9-12 refer to the graph below for a population of bacteria exposed to bacteriophages. 9. The viral reproductive strategy used by the bacteriophages is A) the lytic cycle B) conjugation C) lysogenic cycle D) transformation 10. Which of the following predictions indicates what would happen to the the bacterial population in the figure if the bacteriophages were never introduced? A) The line on the graph indicating bacterial growth would go through cycles of drastic increases in growth and sharp declines. B) The bacterial population would have continued to increase due to the absence of the predator. C) The bacterial population size would still have dropped due to depleted resources. D) The population size would have stayed relatively close to what it was when the graph indicates the virus was added. 3

18 Version B 11. Which of the following explanations best describes why the bacterial population was able to reach carrying capacity again after the initial attack? A) The bacterial cells, after some time, are able to fight off the viral attack through phagocytosis. B) The virus particles ran out of available resources in which to obtain energy. C) The virus particles are only able to infect a certain number of bacterial cells and once those cells die, the rest are able to repopulate. D) Some bacteria either acquire resistant mutations or are innately immune to the viruses and thus survive and repopulate. 12. After some time, the bacterial and virus populations seem to reach an equilibrium. Which of the following explanations best describes a possible reason for this. A) All of the bacteria have become immune to the virus particles. B) A lysogenic situation occurs where the viral genetic material gets incorporated into the host cell genome. C) The virus particles are no longer infecting the bacterial cells. D) This is what is known as a lag phase and is the precursor to another major bacterial population decline. 4

19 Version B Questions refer to the following scenario. A scientist is using an ampicillin-sensitive strain of bacteria that cannot use lactose because it has a nonfunctional gene in the lac operon. She has two plasmids. One contains a functional copy of the affected gene of the lac operon, and the other contains the gene for ampicillin resistance. Using restriction enzymes and DNA ligase, she forms a recombinant plasmid containing both genes. She then adds a high concentration of the plasmid to a tube of the bacteria in a medium for bacterial growth that contains glucose as the only energy source. This tube (+) and a control tube (-) with similar bacteria but no plasmid are both incubated under the appropriate conditions for growth and plasmid uptake. The scientist then spreads a sample of each bacterial culture (+ and -) on each of the three types of plates indicated below. 13. If the scientist had forgotten to use DNA ligase during the preparation of the recombinant plasmid, bacterial growth would most likely have occurred on which of the following? A) 1 and 2 only B) 1 and 4 only C) 4 and 5 only D) 1, 2, and 3 only 5

20 Version B 14. If the scientist used the cultures to perform another experiment as shown above, using medium that contained lactose as the only energy source, growth would most likely occur on which of the following plates? A) 10 only B) 7 and 8 only C) 7 and 9 only D) 8 and 10 only 15. The scientist used restriction enzymes for what purpose in the experiment? A) To make the plasmid small enough to transform cells B) To make cuts in the plasmid DNA C) To make the plasmid enter the cells D) To enable the fragments of DNA to form ionic bonds 16. If no new mutations occur, it would be most reasonable to expect bacterial growth on which of the following plates? 17. A tobacco plant can be made to express a gene from fireflies, resulting in the emission of light. Which of the following is the basis for this phenomenon? A) Chloroplasts can be made to produce light if firefly proteins are injected into plant cells. B) Fireflies and tobacco plants share a recent common ancestor. C) Fireflies and tobacco plants are infected by the same kinds of bacteria. D) Transcription and translation are fundamentally similar in both fireflies and tobacco plants. A) 1 and 2 only B) 3 and 4 only C) 5 and 6 only D) 1, 2, 3, and 4 6

21 Version B Questions refer to the following scenario. In 1928, Fredrick Griffith performed an experiment to determine whether pathogenicity can be conferred between two different strains of a bacterium (Streptococcus pneumoniae). One strain, the S (smooth) strain was known to cause pneumonia in mice due the presence of a protein capsule. The other strain, the R (rough) strain lacked a protein capsule and did not cause the mice to die of pneumonia. Procedure I: Procedure II: Procedure III: Procedure IV: Mice were given living S cells. These mice died. Mice were given living R cells. These mice survived. Mice were given heat-killed S cells. These mice survived. Mice were given a mixture of heat-killed S cells and living R cells. These mice died. 18. Which of the following explains why, at the beginning of the experiment, the living S cells were pathogenic and the living R cells were not? A) The S cells had capsules around them which served as protection against the animal s immune system. B) The R cells were slower than the S cells are were not able to outrun the white blood cells. C) The R cells lacked certain enzymes, which the S cells had. D) The S cells were the only ones carrying the disease-causing gene. 19. What was Griffith s purpose for injecting mice with heat-killed S cells? A) To fix the capsule in place so that it would be able to infect the mice more efficiently. B) This served as the positive control by showing that no matter whether the S cells were heat-killed or not, they caused death to the mice. C) To demonstrate that the transforming factor is a protein. D) This served as the negative control by showing that mice injected with heat-killed S cells did not die. 20. A reasonable conclusion to draw from the results of the experiment is that A) the S cells incorporated a plasmid from the R cells and used it to make the outer capsule. B) the R cells built a capsule out of their own DNA. C) heat-killed S cells are no longer able to confer pathogenicity onto other cells. D) the R cells incorporated a plasmid from the heat-killed S cells and used it to produce their own capsules. 7

22 Version B Questions 21 and 22 refer to the figure below showing the two main reproductive strategies of a bacteriophage. 21. Which of the following best depicts the sequence of events for the reproduction of a virus? I) The viral mrna is then translated into protein (parts of the capsid, tail fibers, etc.). II) The virus injects itself, or its genetic material, into a host cell. III) The new virus particles burst out of the cell (lyse) and are able to go and infect other healthy cells. IV) The viral DNA is encased inside capsid proteins and all the parts are assembled to make multiple virus particles. V) The genetic material then replicates and/or is transcribed into viral mrna. A) III, IV, V, I, II B) II, V, I, IV, III C) IV, I, III, II, V D) II, V, I, III, IV 22. Which of the following is a true statement regarding the lysogenic cycle? A) Once the DNA is integrated into the host cell s genome, it immediately goes into the lytic cycle. B) The host cell is unaffected by the new genetic material that it now contains. C) It can increase the pathogenicity of the prokaryote. D) The host cell is allowed to facilitate transcription, but is unable to perform translation. 23. Which of the following explanations describes how RNA viruses increase genetic variation? A) They have higher quantities of plasmids which increase the genetic diversity of the host cell. B) RNA viruses are more likely to be involved in conjugation thus transferring more genetic information to a host cell. C) RNA viruses inject larger amounts of genetic material into host cells thus causing more mutations. D) RNA viruses have higher rates of mutation due to the lack of mechanisms for detecting replication errors. 8

23 Version B 24. Which of the following best describes why the polymerase chain reaction is a standard technique used in molecular biology research? A) It uses inexpensive materials and produces perfect results. B) It can purify specific sections of a DNA molecule. C) It can produce large amounts of specific DNA sequences. D) It can duplicate the entire human genome. 25. Which of the following statements about plasmids is correct? A) They are found only in eukaryotic cells. B) They are synthesized in the endoplasmic reticulum. C) They are self-replicating. D) They are composed of RNA. 26. HIV is a retrovirus. This is a virus whose genetic information is maintained in the form of RNA. Which of the following explains how this type of virus is able to incorporate itself into the host cell s genome? A) The viral RNA is able to incorporate itself directly into the host cell s genome. B) The viral RNA is able to be converted into viral DNA using an enzyme called reverse transcriptase. C) The host cell s DNA polymerase transcribes the viral RNA into DNA. D) The host cell s DNA ligase is able to glue DNA nucleotides onto viral RNA allowing it to attach to the host cell s genome. 27. The enzyme that is found in retroviruses and that is required for the synthesis of DNA from viral RNA is A) DNA polymerase III B) RNA polymerase C) restriction endonuclease D) reverse transcriptase 28. A virologist creates a particular strain of virus that consists of T2 phage DNA and a T4 phage capsid. A particular bacterial population is exposed to this strain. After the lytic cycle is complete, the new bacteriophages would have A) a T2 capsid and T4 DNA. B) a T2 capsid and T2 DNA. C) a T4 capsid and T3 DNA. D) a T4 capsid and T4 DNA. 29. The Mayinga strain of Ebola Zaire is 90% fatal in humans. In October 1989, the virus broke loose at a primate research facility in Reston, Virginia. The monkeys were from the Philippines, where they had contracted Ebola Zaire. On the plane ride from the Philippines to Virginia, the virus evolved into a new strain that was now capable of being airborne. However, much to the surprise of the scientists trying to contain the Reston outbreak, the virus was now 0% fatal in humans. The new strain was called Ebola Reston. Which of the following is a possible explanation for why this virus was able to evolve so quickly? A) This virus has a very high rate of mutation with no error-fixing mechanisms. B) This virus is able to adapt to its surroundings and change its DNA to match the phenotypes that it needs. C) Ebola is able to use reverse transcriptase to translate viral DNA into viral RNA. D) Ebola Zaire was not able to combine/recombine information as they continue to infect the same cells. 9

24 Version B 30. The use of the isotope 32 P as a tracer element in the study of invasion and lysis of bacteria by viruses has shown that A) ATP from bacteriophages is identical to ATP found in eukaryotic cells B) bacteriophage protein enters the bacteria through the cell wall C) bacteriophage nucleic acids enter bacteria prior to lysis D) 32 P accelerates the lytic effect of bacteriophage infection 31. A genetic engineer prepares DNA fragments from two species and mixes them together. Two of the many fragments are shown below. Which of the following statements is correct? A) No sticky ends were produced. B) The two fragments shown above will join by complementary base pairing. C) The two fragments were prepared by two different restriction endonucleases. D) A single restriction endonuclease was used to cut at different location in the two types of DNA 32. The process in which a bacterial cell picks up extraneous DNA from the environment is called A) transformation B) translation C) transcription D) transduction 10

25 AP Biology Biotechnology Unit Exam Part B Directions: These three questions require numeric answers. Calculate the correct answer for each question, and enter your answer on the grid following each question. Examples of correct entry for the grid-in questions are shown below. The actual questions for this exam begin on the next page. Integer Answer Integer Answer Decimal Answer Fraction Answer (1) Test Questions are Copyright by College Entrance Examination Board, Princeton, NJ. All rights reserved. For face-to-face teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is a registered trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permission is granted for individual classroom teachers to reproduce the activity sheets and illustrations for their own classroom use. Any other type of reproduction of these materials is strictly prohibited.

26 Part B Directions: Part B consists of three questions requiring numeric answers. Calculate the correct answer for each question, and enter the line on the answer sheet. 1. Use the graph above to calculate the mean rate of fatality (individual deaths per year) for the eight years between 1988 and Give your answer to the nearest whole number. (1) Test Questions are Copyright by College Entrance Examination Board, Princeton, NJ. All rights reserved. For face-to-face teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is a registered trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permission is granted for individual classroom teachers to reproduce the activity sheets and illustrations for their own classroom use. Any other type of reproduction of these materials is strictly prohibited.

27 2. During a transformation experiment, a student introduces a plasmid that promotes resistance to ampicillin (common antibacterial agent) to E. coli bacterial cells. The solution containing the bacterial cells and the plasmid (0.02 µg of DNA) is spread on a plate containing Luria broth and ampicillin. The student analyzes the results 16 hours later and finds 23 colonies growing on the plate. Calculate the transformation efficiency in # colonies/µg. Give your answer to the nearest whole number. (1) Test Questions are Copyright by College Entrance Examination Board, Princeton, NJ. All rights reserved. For face-to-face teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is a registered trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permission is granted for individual classroom teachers to reproduce the activity sheets and illustrations for their own classroom use. Any other type of reproduction of these materials is strictly prohibited.

28 3. Four more students replicate the transformation experiment from question #2 and calculate their transformation efficiencies. Their results are found in the table below. Student Transformation Efficiency (colonies/µg) Calculate the standard deviation of the results. Give your answer to the nearest whole number. (1) Test Questions are Copyright by College Entrance Examination Board, Princeton, NJ. All rights reserved. For face-to-face teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is a registered trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permission is granted for individual classroom teachers to reproduce the activity sheets and illustrations for their own classroom use. Any other type of reproduction of these materials is strictly prohibited.

29 Name: Period Version C AP* Biology: Biotechnology Directions: Each of the questions or incomplete statements below is followed by four suggested answers or completions. Select the one that is best in each case and enter the appropriate letter in the corresponding space on the answer sheet. 1. Which of the following statements about plasmids is correct? A) They are found only in eukaryotic cells. B) They are synthesized in the endoplasmic reticulum. C) They are self-replicating. D) They are composed of RNA. 2. The process in which a bacterial cell picks up extraneous DNA from the environment is called A) transformation B) translation C) transcription D) transduction (1)Test Questions are Copyright by College Entrance Examination Board, Prenceton, NJ. All rights reserved. For face-to-fact teaching purposes, classroom teachers are permitted to reproduce the questions. Web or Mass distribution prohibited. (2) AP is registered traemark of the College Entrance Examination Borard. The College Entrance Examination Board was not involved in the production of and does not endorse this product. Permissionis granted of individual classroom teahcers to reproduce the activity sheets and illustation for their own classroom use. Any other type of reproduction of these material is strictly prohibited. 1

30 Version C Questions 3-5 refer to the electrophoresis gel below. An experiment was performed to separate four samples of viral DNA fragments each radioactively labeled with 32 P. The fragments were separated by gel electrophoresis. 3. The electrophoretic separation of the pieces of DNA in each of the four samples was achieved because of differential migration of the DNA fragments in an electric field. This differential migration was caused by the A) relative amounts of radioactivity in the DNA B) number of cleavage points per fragment C) size of each fragment D) overall positive charge of each fragment 4. Which of the following would be a possible explanation for the single band shown for Sample 3? A) The restriction enzyme being used did not make any cuts along the DNA strand. B) The electrodes could have been switched in the middle of the experiment. C) Sample 3 did not contain enough DNA polymerase to facilitate this experiment. D) Sample 3 could be recombinant DNA which does not separate correctly during this procedure. 5. The DNA was labeled with 32 P in order to A) visualize the fragments B) stimulate DNA replication C) inhibit the uptake of unlabeled ATP D) show which fragments included the 5 end and which fragments included the 3 end 2

31 Version C Questions 6-9 refer to the following scenario. A student uses restriction enzymes to cut a DNA molecule into fragments. The digested DNA is loaded into the wells of an agarose gel and the gel is subjected to an electric current. Upon completion of the run, the gel is stained. 6. The type and density of the gel are important because A) they influence the rate of migration of the fragments B) they may cause some DNA molecules to replicate C) some DNA nucleotides may be lost due to chemical reactions with the gel D) some DNA molecules may sink to the bottom and not migrate 7. The procedures described can be used to do all of the following EXCEPT A) isolate and purify certain DNA fragments B) synthesize novel DNA molecules C) study the activity of restriction enzymes D) calculate the size of DNA fragments 8. Which of the following is true of the dye used to stain the fragments? A) It increases the contrast between the agar and the DNA fragments. B) It must be accounted for when calculating the molecular weight of the fragments. C) Its charged areas interfere with the migration of the DNA. D) It is bonded only to the sticky ends of the fragments and can directly determine the sequence of the DNA fragments. 9. The rate of migration of the DNA fragments through the agarose gel is determined by the A) ratio of adenine to cytosine in the fragment B) presence of hydrogen bonds between base pairs C) length of time the electrophoresis unit is allowed to operate D) number of nucleotides in the fragment 10. A genetic engineer prepares DNA fragments from two species and mixes them together. Two of the many fragments are shown below. Which of the following statements is correct? A) No sticky ends were produced. B) The two fragments shown above will join by complementary base pairing. C) The two fragments were prepared by two different restriction endonucleases. D) A single restriction endonuclease was used to cut at different location in the two types of DNA 11. The use of the isotope 32 P as a tracer element in the study of invasion and lysis of bacteria by viruses has shown that A) ATP from bacteriophages is identical to ATP found in eukaryotic cells B) bacteriophage protein enters the bacteria through the cell wall C) bacteriophage nucleic acids enter bacteria prior to lysis D) 32 P accelerates the lytic effect of bacteriophage infection 3

32 Version C 12. Which of the following best describes why the polymerase chain reaction is a standard technique used in molecular biology research? A) It uses inexpensive materials and produces perfect results. B) It can purify specific sections of a DNA molecule. C) It can produce large amounts of specific DNA sequences. D) It can duplicate the entire human genome. Questions refer to the graph below for a population of bacteria exposed to bacteriophages. 13. The viral reproductive strategy used by the bacteriophages is A) the lytic cycle B) conjugation C) lysogenic cycle D) transformation 14. Which of the following explanations best describes why the bacterial population was able to reach carrying capacity again after the initial attack? A) The bacterial cells, after some time, are able to fight off the viral attack through phagocytosis. B) The virus particles ran out of available resources in which to obtain energy. C) The virus particles are only able to infect a certain number of bacterial cells and once those cells die, the rest are able to repopulate. D) Some bacteria either acquire resistant mutations or are innately immune to the viruses and thus survive and repopulate. 4

33 Version C 15. Which of the following predictions indicates what would happen to the the bacterial population in the figure if the bacteriophages were never introduced? A) The line on the graph indicating bacterial growth would go through cycles of drastic increases in growth and sharp declines. B) The bacterial population would have continued to increase due to the absence of the predator. C) The bacterial population size would still have dropped due to depleted resources. D) The population size would have stayed relatively close to what it was when the graph indicates the virus was added. 16. After some time, the bacterial and virus populations seem to reach an equilibrium. Which of the following explanations best describes a possible reason for this. A) All of the bacteria have become immune to the virus particles. B) A lysogenic situation occurs where the viral genetic material gets incorporated into the host cell genome. C) The virus particles are no longer infecting the bacterial cells. D) This is what is known as a lag phase and is the precursor to another major bacterial population decline. Questions 17 and 18 refer to the figure below showing the two main reproductive strategies of a bacteriophage. 17. Which of the following best depicts the sequence of events for the reproduction of a virus? I) The viral mrna is then translated into protein (parts of the capsid, tail fibers, etc.). II) The virus injects itself, or its genetic material, into a host cell. III) The new virus particles burst out of the cell (lyse) and are able to go and infect other healthy cells. IV) The viral DNA is encased inside capsid proteins and all the parts are assembled to make multiple virus particles. V) The genetic material then replicates and/or is transcribed into viral mrna. A) III, IV, V, I, II B) II, V, I, IV, III C) IV, I, III, II, V D) II, V, I, III, IV 5

34 Version C 18. Which of the following is a true statement regarding the lysogenic cycle? A) Once the DNA is integrated into the host cell s genome, it immediately goes into the lytic cycle. B) The host cell is unaffected by the new genetic material that it now contains. C) It can increase the pathogenicity of the prokaryote. D) The host cell is allowed to facilitate transcription, but is unable to perform translation. 19. A tobacco plant can be made to express a gene from fireflies, resulting in the emission of light. Which of the following is the basis for this phenomenon? A) Chloroplasts can be made to produce light if firefly proteins are injected into plant cells. B) Fireflies and tobacco plants share a recent common ancestor. C) Fireflies and tobacco plants are infected by the same kinds of bacteria. D) Transcription and translation are fundamentally similar in both fireflies and tobacco plants. 20. HIV is a retrovirus. This is a virus whose genetic information is maintained in the form of RNA. Which of the following explains how this type of virus is able to incorporate itself into the host cell s genome? A) The viral RNA is able to incorporate itself directly into the host cell s genome. B) The viral RNA is able to be converted into viral DNA using an enzyme called reverse transcriptase. C) The host cell s DNA polymerase transcribes the viral RNA into DNA. D) The host cell s DNA ligase is able to glue DNA nucleotides onto viral RNA allowing it to attach to the host cell s genome. 6

35 Version C Questions refer to the following scenario. A scientist is using an ampicillin-sensitive strain of bacteria that cannot use lactose because it has a nonfunctional gene in the lac operon. She has two plasmids. One contains a functional copy of the affected gene of the lac operon, and the other contains the gene for ampicillin resistance. Using restriction enzymes and DNA ligase, she forms a recombinant plasmid containing both genes. She then adds a high concentration of the plasmid to a tube of the bacteria in a medium for bacterial growth that contains glucose as the only energy source. This tube (+) and a control tube (-) with similar bacteria but no plasmid are both incubated under the appropriate conditions for growth and plasmid uptake. The scientist then spreads a sample of each bacterial culture (+ and -) on each of the three types of plates indicated below. 21. If the scientist used the cultures to perform another experiment as shown above, using medium that contained lactose as the only energy source, growth would most likely occur on which of the following plates? A) 10 only B) 7 and 8 only C) 7 and 9 only D) 8 and 10 only 7