FINAL 07 2020, questions and answers PDF

Preview

Summary

Module_7_ Ch_20_and_18.5...

Description

6/13/2020

Module #7: Ch 20 and 18.5

Module #7: Ch 20 and 18.5 Due: 11:59pm on Thursday, July 1, 2021 You will receive no credit for items you complete after the assignment is due. Grading Policy

Activity: Cloning a Gene in Bacteria

Click here to complete this activity. Then answer the questions.

Part A In order to insert a human gene into a plasmid, both must _____ ANSWER:

have identical DNA sequences originate from the same type of cell code for the same gene product be cut by the same restriction enzyme be the same length

Correct Doing so will result in the formation of complementary sticky ends.

Part B What enzyme forms covalent bonds between restriction fragments? ANSWER:

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

1/20

6/13/2020

Module #7: Ch 20 and 18.5

DNA primase DNA helicase single-stranded binding protein DNA polymerase DNA ligase

Correct DNA ligase catalyzes the formation of covalent bonds between restriction fragments.

Part C Click on the diagram to start the animation. What name is given to the process shown in this animation?

ANSWER:

transduction translation conjugation cloning transformation

Correct Transformation is the process by which a bacterium takes up a plasmid from the surrounding solution.

Part D Click on the diagram to start the animation. What name is given to the process shown in this animation?

ANSWER:

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

2/20

6/13/2020

Module #7: Ch 20 and 18.5

transduction translation conjugation cloning transformation

Correct Cloning occurs with the replication of a recombinant plasmid.

Activity: Restriction Enzymes

Click here to complete this activity. Then answer the questions.

Part A The unpaired nucleotides produced by the action of restriction enzymes are referred to as _____. ANSWER:

sticky ends base sequences single strands restriction fragments ligases

Correct They are called sticky ends since they will "stick" to a complementary single-stranded sequence.

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

3/20

6/13/2020

Module #7: Ch 20 and 18.5

Part B The sticky end of the DNA restriction fragment shown here will pair with a DNA restriction fragment with the sticky end _____.

ANSWER:

-ACGT -AAAA -ACGU -GTAC -TGCA

Correct The matching of sticky ends follows the rules of specific base pairing.

Activity: The Polymerase Chain Reaction

Click here to view this animation. Then answer the questions.

Part A What information can not be obtained from the sequence of a gene?

Hint 1. What information cannot be derived from the sequence of bases in a gene?

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

4/20

6/13/2020

Module #7: Ch 20 and 18.5

ANSWER: Effects of mutation on gene function. Relationship between two species. Whether the gene is methylated. Amino acid sequence of the protein.

Correct Although the gene’s sequence may reveal the presence of methylation targets like cytosine (C), it does not give information about whether such bases have been methylated.

Part B What is the polymerase chain reaction (PCR)?

Hint 1. What can be accomplished by doing PCR?

ANSWER:

A method to determine the sequence of bases in a gene. A method to propagate a gene in bacteria. A method to amplify a fragment of DNA. A method to join two fragments of DNA together.

Correct PCR is an in vitro DNA synthesis reaction that produces many copies of a single DNA fragment.

Part C True or false? Comparison of the sequences of the same gene across species can give some insight into the existence of a common ancestor with that gene.

Hint 1. What conclusions can be drawn if a gene is found in several different species?

ANSWER:

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

5/20

6/13/2020

Module #7: Ch 20 and 18.5

True False

Correct DNA sequence comparisons are a powerful tool by which to estimate how closely related different species are along the evolutionary timeline.

Part D True or false? The Taq enzyme is a type of DNA polymerase that allows researchers to separate the DNA strands during the annealing step of the PCR cycle without destroying the polymerase.

Hint 1. Consider which step of PCR takes place at the highest temperature.

ANSWER:

True False

Correct Taq polymerase is derived from a species of bacteria living in hot springs, which makes it stable at the high temperature required for the denaturation step of PCR.

Part E How many DNA molecules would there be after four rounds of PCR if the initial reaction mixture contained two molecules?

Hint 1. Diagram the DNA molecules as they are amplified in each round.

ANSWER:

32 8 16 64

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

6/20

6/13/2020

Module #7: Ch 20 and 18.5

Correct Thirty-two DNA molecules are produced if two molecules are doubled four times.

Part F During which step in the PCR cycle are nucleotides used?

Hint 1. Remember that nucleotides are used to make DNA strands.

ANSWER:

All of these steps. Extension. Denaturation. Annealing.

Correct Nucleotides are used to synthesize the complementary strand to the DNA template during the extension step.

Part G During which step in the PCR cycle do primers form bonds with a single-stranded template?

Hint 1. Primers are short, single-stranded DNA molecules.

ANSWER:

All of these steps. Extension. Denaturation. Annealing.

Correct Primers form hydrogen bonds with the single-stranded DNA template during the annealing step.

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

7/20

6/13/2020

Module #7: Ch 20 and 18.5

Activity: Producing Human Growth Hormone

Click here to view this animation. Then answer the questions.

Part A What defect causes pituitary dwarfism?

Hint 1. What is missing in affected individuals?

ANSWER:

Lack of a pituitary gland Lack of growth hormone One defective allele Neurodegeneration

Correct Affected individuals produce little or no growth hormone.

Part B What is genetic cloning?

Hint 1. What is accomplished when a gene is cloned?

ANSWER: https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

8/20

6/13/2020

Module #7: Ch 20 and 18.5

A method to produce many copies of a gene A method to grow a large amount of protein A method to find the gene that encodes a certain protein

Correct Genetic cloning is the process by which many identical copies of a gene are produced.

Part C True or false? The use of growth hormone isolated from cadavers was banned mainly because there were not enough cadavers to supply the hormone.

Hint 1. What were the negative effects of using growth hormone isolated from human cadavers?

ANSWER:

True False

Correct The use of growth hormone isolated from cadavers was banned mainly because the isolated hormone was potentially contaminated with prion proteins.

Part D Which of the following statements best describes the function of reverse transcriptase?

Hint 1. The enzyme is used in the construction of cDNA libraries; consider its name to deduce its function.

ANSWER:

It seals DNA fragments together. It makes complementary DNA (cDNA) from mRNA. It synthesizes double-stranded DNA molecules from single-stranded DNA molecules. It cuts DNA strands at specific sequences.

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

9/20

6/13/2020

Module #7: Ch 20 and 18.5

Correct The function of reverse transcriptase is similar to the reverse of transcription; it makes a single strand of complementary DNA (cDNA) from mRNA.

Part E Which of the following steps would be performed last when screening a cDNA library?

Hint 1. Researchers screen a cDNA library to isolate a specific gene from a collection of DNA sequences.

ANSWER:

Match the region of radioactivity on the filter with the corresponding plate. Spread bacterial cells containing the library on a plate to form colonies. Treat DNA on the filter to make it single-stranded. Incubate the filters with a gene-specific probe.

Correct This step allows researchers to match the colony on the filter with the colony of the bacterial plate so the correct colony can be grown for further study. It would be the last step in screening a cDNA library.

Part F How can large quantities of protein be produced from a bacterial colony containing the gene of interest?

Hint 1. Think about how a protein can be produced in a microscopic "factory."

ANSWER:

Construct a probe that matches part of the gene's sequence. Insert the plasmid containing the cDNA into bacteria. Use reverse transcriptase to make cDNAs. Put a cDNA encoding the protein into a plasmid with a bacterial promoter sequence.

Correct Once a cDNA is put into a plasmid with a bacterial promoter, the bacteria will transcribe and translate the gene. https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

10/20

6/13/2020

Module #7: Ch 20 and 18.5

Part G True or false? The term "sticky ends" refers to the overhanging ends on DNA that are generated by restriction enzymes, which can base pair with any DNA molecules that contain complementary sticky ends.

Hint 1. The "sticky ends" on both the gene to be cloned and the bacterial plasmid allow the gene to be inserted into the bacterial plasmid.

ANSWER:

True False

Correct Restriction enzymes cut DNA and generate "sticky ends," which can then base pair with DNA molecules that contain the same sticky ends.

Activity: Analyzing DNA Fragments Using Gel Electrophoresis

Click here to complete this activity. Then answer the questions.

Part A In this example the marker DNA includes fragments that have 23,130, 9,416, 6,557, 4,361, 2,322, 2,027, and 564 base pairs. Approximately how many base pairs are in the DNA fragment indicated by the letter A?

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

11/20

6/13/2020

Module #7: Ch 20 and 18.5

ANSWER:

564 2,027 2,322 6,557 9,416

Correct DNA fragment A moved about the same distance as the third-longest marker DNA fragment.

Part B In this example the marker DNA includes fragments that have 23,130, 9,416, 6,557, 4,361, 2,322, 2,027, and 564 base pairs. Approximately how many base pairs are in the DNA fragment indicated by the letter B?

ANSWER:

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

12/20

6/13/2020

Module #7: Ch 20 and 18.5

between 23,130 and 9,416 base pairs between 9,416 and 6,557 base pairs between 6,557 and 4,361 base pairs between 4,361 and 2,322 base pairs between 2,322 and 2,027 base pairs

Correct DNA fragment B moved farther than the 6,557 base pair marker fragment but not as far as the 4,361 base pair marker fragment.

Part C DNA fragment B consists of _____ base pairs.

ANSWER:

564 1,268 1,405 2,027 2,322

Correct Reading the calibration curve should give you a value of 1,405 base pairs for this DNA fragment.

Activity: DNA Fingerprinting

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

13/20

6/13/2020

Module #7: Ch 20 and 18.5

Click here to complete this activity. Then answer the questions.

Part A This is a DNA fingerprint exhibiting samples from a victim, two suspects, and the crime scene. Which of these DNA fragments is common to both the victim and Suspect 1?

ANSWER:

A B C D E

Correct A visual comparison of the gel electrophoresis results should reveal that Suspect 1 has a DNA fragment that matches victim DNA fragment B.

Part B This is a DNA fingerprint exhibiting samples from a victim, two suspects, and the crime scene. Which of these DNA fragments is common to both the victim and Suspect 2?

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

14/20

6/13/2020

Module #7: Ch 20 and 18.5

ANSWER:

A B C D E

Correct A visual comparison of the gel electrophoresis results should reveal that Suspect 2 has a DNA fragment that matches victim DNA fragment C.

Part C Why is Suspect 1 considered more likely to have committed the crime than Suspect 2?

ANSWER:

The crime scene sample contains DNA fragments from both the victim and Suspect 1. The crime scene sample contains DNA fragments from both the victim and Suspect 2. Suspect 1 and the victim have more DNA fragments in common that do the victim and Suspect 2. Suspect 2 and the victim have more DNA fragments in common that do the victim and Suspect 1. Suspect 1 and Suspect 2 have more DNA fragments in common than either have in common with the victim.

Correct Such a good match between crime scene DNA fragments and Suspect 1 DNA fragments strongly suggest that Suspect 1 committed the crime.

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

15/20

6/13/2020

Module #7: Ch 20 and 18.5

Activity: Making Decisions About DNA Technology: Golden Rice

Click here to complete this activity. Then answer the questions.

Part A Why is golden rice pale yellow in colour? ANSWER:

It is rich in chlorophyll a. It is nutrient-poor. It is rich in beta-carotene. It is rich in chlorophyll b. It is rich in phycobilins.

Correct Beta-carotene confers a yellow colour on the rice.

Part B Which of these is a symptom of vitamin A deficiency? ANSWER:

osteoporosis impaired taste perception overstimulation of the immune system blindness impaired blood clotting

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

16/20

6/13/2020

Module #7: Ch 20 and 18.5

Correct Chronic vitamin A deficiency can lead to blindness.

Part C Which of these is a vitamin A precursor? ANSWER:

cobalamin pyridoxine plasmid beta-carotene thiamin

Correct The body can convert beta-carotene into vitamin A.

Part D The transfer of antibiotic-resistant genes from genetically engineered bacteria to disease-causing bacteria _____. ANSWER: would, if it occurred, be no cause for concern has occurred is likely to occur can never occur seems unlikely

Correct It seems unlikely to occur and there is no evidence that it has occurred.

Current Events: A Race to Save the Orange by Altering Its DNA (New York Times, 7/27/2013) Read this New York Times article and then answer the questions. A Race to Save the Orange by Altering Its DNA (New York Times, 7/27/2013)

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

17/20

6/13/2020

Module #7: Ch 20 and 18.5

Registration with The New York Times provides instant access to breaking news with NYTimes.com. To register, go to http://www.nytimes.com/register. Visit http://www.nytimes.com/content/help/rights/terms/terms-of-service.html to review the current NYT Terms of Service.

Part A Why have Florida citrus farmers been using more pesticides? ANSWER:

In an effort to kill the organism that spreads citrus greening. In an effort to kill the organism that causes citrus greening. In an effort to promote healthy plant growth surrounding their trees. In an effort to make trees resistant to citrus greening.

Correct

Part B Which of the following techniques are scientists using to disrupt the DNA in crop species in the hope of speeding up evolution? ANSWER:

Dousing the plants with excess ripening hormones. Giving the plants large doses of antibiotics. Bombarding the plants with radiation. Keeping the plants out of the sun.

Correct

Part C You are buying groceries at a typical American grocery store. Which of the following foods is most likely to be genetically modified or contain genetically modified ingredients? ANSWER:

brown rice flour an apple corn meal wheat germ

https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

18/20

6/13/2020

Module #7: Ch 20 and 18.5

Correct

Part D You are a member of Greenpeace and wish to organize a protest outside of the federal agency in charge of food labeling in the U.S. Where should you take your group of protestors? ANSWER:

Department of Health and Human Services Food and Drug Administration United States Department of Agriculture Environmental Protection Agency

Correct

Part E Utilizing a gene from which of the following currently appears to offer the most hope of saving Florida's orange trees from citrus greening? ANSWER:

tomato a virus bacterium spinach

Correct

Chapter 20 Pre-Lecture Question 7 Part A If cells from a carrot are removed and placed in a culture medium, they can develop into a normal adult plant. This demonstrates that carrot cells _____.

Hint 1. Consider the cell-level requirements for the development of an adult of any species.

ANSWER: https://session.masteringbiology.com/myct/assignmentPrintView?assignmentID=8245656

19/20

6/13/2020

Module #7: Ch 20 and 18.5

differ genetically at maturity retain all the genes that were in the zygote that developed into the original plant differ as mature cells are undifferentiated as adult cells differentiate

Correct Furthermore, the carrot cells are totipotent.

Chapter 20 Pre-Lecture Question 9 Part A You are a member of the jury for a murder case. The prosecution has presented DNA evidence linking the defendant to the crime scene. The defense claims that DNA evidence using STR analysis with 13 markers is not sufficient to reliably distinguish between people. What do you think?

Hint 1. The more markers used, the lower the probability that 2 people will have exactly the same pattern.

ANSWER:

The prosecution is right. STR analysis with 13 markers gi...