Genetics From Genes to Genomes 2nd Canadian Edition By Leland Hartwell - Test Bank

Genetics From Genes to Genomes 2nd Canadian Edition By Leland Hartwell – Test Bank

 

Instant Download – Complete Test Bank With Answers

 

 

Sample Questions Are Posted Below

 

Chapter 05

The Multifaceted Nature of the DNA Molecule

 

 

Multiple Choice Questions

1. Which of the following is not true of DNA?
   A.It is acidic.
   B. It contains deoxyribose.
   C. It is found in cell nuclei.
   D. It contains phosphate.
   E. It contains proteins.

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-01 Evaluate and appraise the evidence supporting the hypothesis that DNA is the genetic material.
Topic: 05-02 Chemical studies locate DNA in chromosomes

2. The molecule of heredity is
   A.RNA.
   B. DNA.
   C. protein.
   D. carbohydrate.
   E. lipid.

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-01 Evaluate and appraise the evidence supporting the hypothesis that DNA is the genetic material.
Topic: 05-02 Chemical studies locate DNA in chromosomes

 

3. The four subunits that compose DNA are called
   A.phosphodiesters.
   B. proteins.
   C. nucleotides.
   D. nucleosides.
   E. polymers.

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-01 Evaluate and appraise the evidence supporting the hypothesis that DNA is the genetic material.
Topic: 05-03 Bacterial transformation implicates DNA as the genetic material

4. DNA is localized mainly in the
   A.cell membrane.
   B. endoplasmic reticulum.
   C. vacuoles.
   D. chromosomes.
   E. chromatin.

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-01 Evaluate and appraise the evidence supporting the hypothesis that DNA is the genetic material.
Topic: 05-02 Chemical studies locate DNA in chromosomes

5. Each nucleotide of DNA contains
   A.a deoxyribose sugar only
   B. a nitrogenous base only
   C. a phosphate only
   D. a deoxyribose sugar, a nitrogenous base and a phosphate
   E. amino acids

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-07 The DNA helix consists of two antiparallel chains

 

6. The polarity of DNA synthesis is
   A.5’®3′
   B. 3’®5′
   C. 5’®2′
   D. 2’®5′
   E. 1’®5′

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-07 The DNA helix consists of two antiparallel chains

7. If a double stranded RNA genome is isolated from a virus and is found to contain 15% uracil, what percentage of its genome is guanine?
   A.10
   B. 35
   C. 20
   D. 40
   E. 80

 

Blooms: Apply
Difficulty: Medium
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-13 In some viruses, RNA is the repository of genetic information

8. The ratio of _____ is 1:1.
   A.guanine to adenine
   B. adenine to thymine
   C. cytosine to adenine
   D. uracil to cytosine
   E. Uracil to uracil.

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-07 The DNA helix consists of two antiparallel chains

 

9. X-ray data showed that the spacing between repeating units along the axis of the DNA helix is
   A.2.0 angstroms.
   B. 3.4 angstroms.
   C. 20 angstroms.
   D. 34 angstroms.
   E. 0 angstroms.

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-06 Nucleotides are the building blocks of DNA

10. X-ray data showed that the DNA helix undergoes one complete turn every
    A.2.0 angstroms.
    B. 3.4 angstroms.
    C. 20 angstroms.
    D. 34 angstroms.
    E. 1000 angstroms

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-06 Nucleotides are the building blocks of DNA

11. ________ bonds are responsible for the chemical affinity between A and T (or G and C) nucleotides.
    A.Ionic
    B. Covalent
    C. Hydrogen
    D. Electro-ionic
    E. Double

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-07 The DNA helix consists of two antiparallel chains

 

12. Which one of the following is not an element (atom) found in DNA?
    A.oxygen
    B. sulphur
    C. nitrogen
    D. phosphorous
    E. hydrogen

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-06 Nucleotides are the building blocks of DNA

13. _______ -form DNA spirals to the right and is the major form of naturally occurring DNA molecules.
    A.A
    B. B
    C. D
    D. Y
    E. Z

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-07 The DNA helix consists of two antiparallel chains

14. The nucleotide that is present in RNA but not DNA is
    A.thymine.
    B. uracil.
    C. adenine.
    D. cytosine.
    E. guanosine.

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-07 The DNA helix consists of two antiparallel chains

 

15. DNA replication occurs through a _________ process.
    A.conservative
    B. semiconservative
    C. dispersive
    D. transferal
    E. quadriconservative

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-14 DNA Replication

16. During complementary base-pairing, enzymes join the base’s nucleotide to the preceding nucleotide by a(n) __________ bond.
    A.hydrogen
    B. ionic
    C. phosphodiester
    D. electrostatic
    E. double helical

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-15 Overview: Complementary base-pairing ensures semiconservative replication

17. During early interphase, the state of the DNA can be described as
    A.a single continuous linear double helix.
    B. a double helix replicated semiconservatively.
    C. a double helix replicated conservatively.
    D. single-stranded DNA.
    E. single-strand RNA

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-15 Overview: Complementary base-pairing ensures semiconservative replication

 

18. During the S phase of interphase, the state of the DNA can be described as
    A.a single continuous linear double helix.
    B. a double helix replicated semiconservatively.
    C. a double helix replicated conservatively.
    D. a triple helix replicated semiconservatively.
    E. a triple helix replicated conservatively

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-15 Overview: Complementary base-pairing ensures semiconservative replication

19. The step in DNA replication in which the replication proteins open up the double helix and prepare for complementary base-pairing is called
    A.initiation.
    B. elongation.
    C. termination.
    D. translation.
    E. translocation.

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-15 Overview: Complementary base-pairing ensures semiconservative replication
Topic: 05-18 DNA replication is a tightly regulated, complex process

20. The step in DNA replication in which the proteins connect the correct sequence of nucleotides into a continuous new strand is called
    A.initiation.
    B. elongation.
    C. termination.
    D. translation.
    E. translocation.

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

 

21. The step in DNA replication in which two replication forks moving in opposite directions may meet is called
    A.initiation.
    B. elongation.
    C. termination.
    D. translation.
    E. translocation.

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

22. How many replication forks depart from an origin of replication?
    A.one
    B. two
    C. three
    D. four
    E. five

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

23. The protein that progressively unwinds DNA ahead of each replication fork is called
    A.primase.
    B. helicase.
    C. topoisomerase.
    D. telomerase.
    E. ligase.

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

 

24. Which of the following is not involved in ensuring the accuracy of a cell’s genetic information?
    A.redundancy
    B. repair enzymes
    C. precision of replication machinery
    D. DNA polymerase proofreading mechanism
    E. transformation

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

25. If 35% of the bases in a region of the mouse genome are cytosine, what percentage in that region are adenine?
    A.15%
    B. 20%
    C. 30%
    D. 35%
    E. 70%

 

Blooms: Apply
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-08 The double helix may assume alternative forms

26. The complementary sequence of 5′ AATTCGCTTA 3′ is
    A.5′ AATTCGCTTA 3′.
    B. 3′ AATTCGCTTA 5′.
    C. 5′ TAACGCTTAA 3′.
    D. 5′ TAAGCGAATT 3′.
    E. 3′ TAAGCGAATT 5′.

 

Blooms: Apply
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

 

27. A guanine can only pair with _____.
    A.Cytosine
    B. Adenine
    C. Guanine
    D. Thymine
    E. Uracil

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-07 The DNA helix consists of two antiparallel chains

28. An adenine in the DNA would pair with _____ in RNA.
    A.Uracil
    B. Thymine
    C. Guanine
    D. Cytosine
    E. Adenine

 

Blooms: Apply
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-07 The DNA helix consists of two antiparallel chains

29. Who demonstrated that DNA, rather than protein, was the genetic material of bacteria?
    A.Avery
    B. Watson
    C. Meselson
    D. Mendel
    E. Franklin

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-01 Evaluate and appraise the evidence supporting the hypothesis that DNA is the genetic material.
Topic: 05-04 Viral studies point to DNA, not protein, in replication

 

30. Which of the following is not true of naturally occurring DNA?
    A.it can be circular
    B. it forms a right-handed helix
    C. it contains hydrogen bonds
    D. it contains ribose
    E. it contains covalent bonds

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-08 The double helix may assume alternative forms
Topic: 05-18 DNA replication is a tightly regulated, complex process

31. Which of these is true of RNA?
    A.it contains thymidine
    B. it contains deoxyribose
    C. it can form double helices
    D. it forms the chromosomes of some bacteria
    E. in eukaryotes, it is synthesized semiconservatively

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

32. The energy for DNA synthesis comes most directly from
    A.deoxyribose
    B. dNTPs
    C. PPi
    D. NADH
    E. ribose

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

 

33. Why is RNA required for DNA replication?
    A.the lagging strand is synthesized as RNA
    B. the double helix must be stabilized by RNA
    C. DNA polymerase can only add nucleotides to an existing chain
    D. single strand DNA must be stabilized as it is synthesized
    E. RNA is converted to DNA after synthesis

 

Blooms: Analyze
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

34. If chromosomal DNA were single stranded, which of the following would be most reduced compared to a double stranded molecule?
    A.informational complexity (e.g. the diversity of proteins encoded)
    B. informational fidelity (e.g. the consistency of sequence between generations)
    C. informational density (e.g. the number of proteins encoded)
    D. ability to replicate information (e.g. the ability to transfer genes to progeny)
    E. structural diversity (e.g. the number of forms into which the molecule could fold)

 

Blooms: Analyze
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

35. By applying an equation formulated by Shannon, the information content of a polymer such as DNA or protein depends on its:
    A.number of monomers in the polymer
    B. number of discrete monomers (e.g. number of different bases or amino acids)
    C. number of discrete monomers and total number of monomers in the polymer
    D. three-dimensional structure of the polymer
    E. three-dimensional structure of the polymer and number of discrete monomers

 

Blooms: Apply
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-07 The DNA helix consists of two antiparallel chains

 

True / False Questions
 

36. A phosphodiester bond joins one nucleotide to another in the DNA polymer.
    TRUE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-01 Evaluate and appraise the evidence supporting the hypothesis that DNA is the genetic material.
Topic: 05-03 Bacterial transformation implicates DNA as the genetic material

37. DNA polymerase moves along the template strand in the 5′—3′ direction
    FALSE

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-17 Synthesis of a new DNA strand is universally unidirectional

38. The RNA primer is synthesized by an RNA polymerase.
    FALSE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-17 Synthesis of a new DNA strand is universally unidirectional

39. DNA polymerase III fills the gap between okazaki fragments.
    FALSE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-17 Synthesis of a new DNA strand is universally unidirectional

 

40. Redundancy provides the basis for checking and repairing errors from chemical alterations.
    TRUE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-17 Synthesis of a new DNA strand is universally unidirectional

41. Pyrimidines are a nitrogenous base containing a double ring, while purines contain a single ring.
    FALSE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-08 The double helix may assume alternative forms

42. Prokaryotes have a circular chromosome surrounded by a nuclear membrane.
    FALSE

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-09 DNA structure is the foundation of genetic function

43. Transformation in bacteria results from the uptake of foreign DNA.
    TRUE

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-01 Evaluate and appraise the evidence supporting the hypothesis that DNA is the genetic material.
Topic: 05-04 Viral studies point to DNA, not protein, in replication

 

44. DNA has a highly negative charge throughout the molecule and therefore has no polarity.
    FALSE

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

45. A region of DNA 100 bp in length has the potential to be represented by 4100 unique sequences.
    TRUE

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-09 DNA structure is the foundation of genetic function

46. Viruses use only DNA as their genetic material.
    FALSE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-09 DNA structure is the foundation of genetic function

47. Human DNA is replicated in a conservative manner.
    FALSE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-15 Overview: Complementary base-pairing ensures semiconservative replication

 

48. In DNA replication, new DNA is produced in a continuous bidirectional fashion.
    FALSE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

49. Okazaki fragments can be joined together by a helicase enzyme.
    FALSE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-18 DNA replication is a tightly regulated, complex process

50. The unwound region of DNA that’s undergoing replication is called replication bubble?
    TRUE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-17 Synthesis of a new DNA strand is universally unidirectional

51. DNA polymerase has no proof reading capacity?
    TRUE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-19 Integrity and accuracy of genetic information must be preserved

 

52. Accuracy of replication is enhanced by the redundancy of DNA, enzymatic repair of damaged DNA, and the remarkable precision of the cellular replication machinery.
    TRUE

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

 

Short Answer Questions

53. Briefly describe the role of an initiator protein in DNA replication.

The initiator protein is the first protein to bind to the origin of replication and attracts helicase, which is able to unwind the region surrounding the origin-the first step in initiation of DNA replication.

 

Blooms: Remember
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-12 Some genetic information is accessible without unwinding DNA

54. During the DNA replication process, RNA primers are removed and replaced with DNA. Briefly state why it is important that this RNA be replaced with DNA.

RNA is more unstable than DNA (it may be easily degraded). DNA must also be present so that the next round of replication may proceed.

 

Blooms: Analyze
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-08 The double helix may assume alternative forms
Topic: 05-18 DNA replication is a tightly regulated, complex process

 

55. Why are DNA molecules considered redundant?

Either strand of the double helix can specify the sequence of the other.

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process

56. A DNA sample has 10% guanine, what is the percentage of Thymine?

40%

 

Blooms: Apply
Difficulty: Medium
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-07 The DNA helix consists of two antiparallel chains

57. Griffith found that smooth (S) forms of S. pneumoniae have a polysaccharide capsule and rough (R) forms do not. Only S forms cause infection. Briefly describe how Griffith demonstrated transformation using live R form and heat-killed S form bacteria.

S (heat killed) HK does not yield infection. R live does not yield infection. S HK + R live = infection; R has been transformed by S.

 

Blooms: Understand
Difficulty: Easy
Learning Objective: 05-01 Evaluate and appraise the evidence supporting the hypothesis that DNA is the genetic material.
Topic: 05-04 Viral studies point to DNA, not protein, in replication

 

58. A pharmacologist manufactures a new drug that has the capacity to block the enzyme helicase. What sort of effect will this drug have?

It will prevent the unwinding of the double helix thus preventing replication from starting.

 

Blooms: Apply
Difficulty: Medium
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-17 Synthesis of a new DNA strand is universally unidirectional

59. What’s the effect of the single stranded DNA binding proteins?

They keep the DNA helix open.

 

Blooms: Apply
Difficulty: Medium
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Learning Objective: 05-04 Discriminate between the conservative, semi-conservative, and dispersive models of DNA replication.
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-18 DNA replication is a tightly regulated, complex process

60. What is meant by a leading strand?

A leading strand adds nucleotides continuously to the growing 3′ end as soon as the unravelling fork exposes the corresponding base.

 

Blooms: Analyze
Difficulty: Easy
Learning Objective: 05-05 Summarize the molecular reactions and interactions that drive the process of DNA replication.
Topic: 05-17 Synthesis of a new DNA strand is universally unidirectional
Topic: 05-18 DNA replication is a tightly regulated, complex process

 

61. Viruses may have RNA, ssDNA, or dsDNA as their molecule of heredity. Design an experiment that would allow you to test an unknown virus and determine which it carried.

Grow bacteria infected with virus in the presence of radioactive uracil. Isolated genetic material from phage will be radioactive if it is an RNA-containing virus. Double stranded versus single stranded DNA can be resolved by the ability to undergo digestion with restriction enzymes.

 

Blooms: Create
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-09 DNA structure is the foundation of genetic function

62. How did Watson and Crick’s scientific approach differ from that of other scientists who studied DNA?

Unlike most other scientists who preceded them, Watson and Crick did very little experimentation; instead their breakthrough came by interpreting the data of others, such as Chargaff’s rules, and Franklin’s X-ray diffraction data.

 

Blooms: Evaluate
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-08 The double helix may assume alternative forms

63. Crick said that “DNA is, at bottom, a much less sophisticated molecule than a highly evolved protein and for this reason reveals its secrets more easily.” How is DNA less complex than protein?

Protein is a polymer of at least 23 different monomers (amino acids), whereas DNA is a polymer of just four types of monomers (bases). The amino acids of protein are chemically much more diverse (e.g. hydrophobicity, acidity, size) than the bases of DNA, which are chemically similar to each other. Proteins therefore can have a greater diversity of structures and chemical functions than DNA has.

 

Blooms: Analyze
Difficulty: Easy
Learning Objective: 05-02 Relate DNA’s overall molecular structure to the chemical properties of the moieties making up a nucleotide.
Topic: 05-08 The double helix may assume alternative forms

 

64. If DNA replication were conservative or dispersive (instead of semiconservative), what would be the results of the Meselson-Stahl experiment?

In the conservative model, there would still be two bands, but the lower band would be at a position consistent with a molecule consisting entirely of ¹⁵N, rather than being at an intermediate position consistent with equal parts ¹⁵N and ¹⁴N. In the case of dispersive replication, there would be many bands distributed between the position of bands consisting of entirely ¹⁵N labelled DNA and ¹⁴N labelled DNA.

 

Blooms: Evaluate
Difficulty: Easy
Learning Objective: 05-03 Relate the molecular structure of DNA to its biological functions.
Topic: 05-18 DNA replication is a tightly regulated, complex process