Chapter 6: DNA: The Molecule of Life

1. The molecule of heredity is ________________, which is a type of __________________________.

2. DNA is a large molecule made from many smaller molecules. Which of the following is used to
construct a molecule of DNA?

A) Chromosomes
B) Nucleotides
C) Double helix
D) Monosaccharides
E) Amino acids

3. Match the following terms with their appropriate descriptions: double helix, base, nucleic acid,
nucleotide, and sugar-phosphate backbone. Some answers may be used more than once or not at all.

A) Molecules that store information: ___________________________________________

B) Consists of a base, a five-carbon sugar, and a phosphate: __________________________________
C) Structure of a double-stranded molecule of DNA: ______________________________________
D) Identical among all DNA molecules: _________________________________________________
E) Individual subunits that make up DNA: __________________________

4. Overall, a molecule of DNA has a negative charge. Which component of a nucleotide gives DNA this
charge?

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 5. A gene is a specific section of DNA that contains the instructions to make a specific molecule. If all
molecules of DNA contain a phosphate group, a deoxyribose, and a base propose an explanation about
how the information to make a specific molecule is coded within the DNA molecule.

6. If cytosine makes up 15% of the bases in a molecule of DNA, what percentage of the bases is adenine?

A) 35%
B) 60%
C) 85%
D) 20%
E) 50%

7. True or false: DNA must be precisely copied prior to being passed on to the next generation. If false,
please correct the statement.

8. If one polynucleotide strand of DNA has ACTTGACTAGCTA as its sequence of bases, what would be
the sequence of bases on the opposing strand?

9. Briefly explain what “rules” allowed you to quickly determine the answer to question 2 above?

10. The process by which a molecule of DNA is copied is known as _____________________________.

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11. Place the following steps of DNA replication in the proper order: DNA fragments are fused together,
double helix is pulled apart, and new strands of DNA are synthesized.

12. A drug that inhibits DNA ligase but not DNA polymerase is added to a cell. Explain what would happen
during DNA replication as a result of this drug.

13. True or false: Nucleic acids store the information to make carbohydrates. If false, please correct the
statement.

14. Two types of nucleic acids that are found in all cells are ______________ and ______________.

15. Which of the following is found in all nucleotides of both RNA and DNA?

A) Phosphate group
B) Ribose
C) Deoxyribose
D) Uracil
E) All of the above

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16. Is the following diagram a nucleotide of DNA, RNA, or could it be either one? Briefly explain your
answer.

17. You are a biochemist and have been given a test tube containing a small amount of nucleic acid. You
have been asked to determine whether it is DNA or RNA. Which of the following would be a
characteristic that indicates RNA? Choose all that apply.

A) Presence of uracil, but no thymine

B) Presence of guanine, but no cytosine
C) Presence of phosphate, but no nitrogen
D) Presence of ribose, but no deoxyribose
E) None of the above

18. True or false: DNA is directly responsible for producing your characteristics. If false, please correct the
statement.

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19. Correct the following diagram that shows the flow of genetic information: RNA → protein → DNA

20. Translation converts the information stored in ____ into ______.

A) DNA; RNA
B) RNA; a protein
C) protein; DNA
D) protein; RNA
E) DNA; a protein

21. Briefly explain why you think “mRNA” is a good name for the RNA copy made from DNA.

22. Complete the following table, which compares transcription and translation.

Transcription Translation

Location

Description

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23. If a strand of DNA has the sequence AAGCTC, transcription will result in which of the following?

A) Single RNA strand with the sequence TTCGAG

B) DNA strand with the sequence TTCGAG
C) Single RNA strand with the sequence UUCGAG
D) DNA strand with the sequence AAGCTC
E) None of the above

24. A series of three nucleotides that specifies an amino acid is a __________________.

25. A student has given a sequence of DNA as follows: AACTAGCTAGCT and is asked to provide the
mRNA copy that would be made from that sequence during transcription. The student provides the
following sequence: TTGATCGATCGA. Is this the correct sequence? If not, please explain why it is
incorrect and fix it.

26. ________________________________ is the process by which information stored in DNA is copied

into mRNA.

27. List the following steps of transcription in order: RNA polymerase makes RNA, mRNA leaves the
nucleus, RNA polymerase binds the promoter, and RNA splicing.

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28. A gene has a sequence of DNA in front of it that directs the RNA polymerase where to begin
transcription. This sequence of DNA is the ______________________.

A) transcription
B) promoter
C) terminator
D) RNA splicing
E) None of the above

29. True or false: The terminator is the sequence of DNA in front of the gene that tells the RNA polymerase
where to begin transcription. If false, please correct the statement.

30. List three ways in which mRNA is modified after transcription.

31. Are introns and exons found in DNA or RNA?

32. True or false: The process of translation occurs within the cytoplasm on a cellular structure known as
the mitochondrion. If false, please correct the statement.

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33. Which of the following RNA molecules is a component of ribosomes?

A) mRNA
B) rRNA
C) tRNA
D) All of the above
E) None of the above

34. A set of three nucleotides that specifies an amino acid is called a ____________________________

35. Which of the following RNA molecules is involved in the process of translation?

A) mRNA
B) rRNA
C) tRNA
D) All of the above RNA molecules are involved in translation.
E) None of the above RNA molecules are involved in translation.

36. Complete the following table, which compares the different kinds of RNA.

mRNA rRNA tRNA

Function

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37. What codon does every mRNA molecule have in common? What amino acid begins every polypeptide?

38. How many codons are in the following mRNA sequence?

AUGGGGCAGGUAUGA

39. Use the information from question 11 to determine how many amino acids would be in the polypeptide
produced from that mRNA.

40. List the steps of translation in the order they occur.

41. A drug that changes the AUG codon to UAC would most likely have what effect on translation? Be
brief but specific in your answer.

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42. Does a stop codon specify an amino acid? If yes, which one? If no, what does a stop codon specify?

43. The mechanism by which cells turn on and off specific genes is known as ________.

44. Briefly explain how every cell in your body has every one of your genes, but different cells can have
very different shapes and functions. _________________________________.

45. True or false: Gene expression refers to making a finished protein from DNA. If false, correct the
statement.

46. Control of gene expression is analogous to controlling a radio. Briefly explain why this is a good
analogy.

47. Would X chromosome inactivation occur in human males? Briefly explain your answer either way.

48. The inactive X chromosome in a human female cell will condense into what structure?

A) Barr body
B) Intron
C) microRNA
D) Exon
E) None of the above

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49. True or false: Cell-to-cell signaling plays a key role in how your cells perform critical functions within
tissues and organs. If false, please correct the statement.

50. A ______________________________________________________ is a series of molecular relays

that bring a message from outside the cell to the nucleus. This signal conveys a message that usually
results in one or more ____________ being turned on or off.

51. Which of the following describes the process by which an animal grows from an embryo into an adult?

A) Induction
B) Homeotic
C) Development
D) Signal transduction
E) None of the above

52. A _______________________ is any change in a cell’s genetic information.

53. True or false: A mutation can be a single nucleotide, groups of nucleotides, and even a large region of a
gene. If false, please correct the statement.

54. Match the following terms with their definition: mutagen, carcinogen, mutation, frameshift mutation,
and point mutation. Some answers may be used more than once.

A) Any agent that causes cancer: ____________________________

B) Where one nucleotide is substituted for another: ____________________________________________
C) A substance that causes a change in DNA: ______________________________________
D) Any change in a sequence of DNA: ______________________________________
E) A change in the DNA that results in the reading frame being altered: ________________________

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55. Complete the following table, which compares the three types of point mutations.

Silent mutation Missense mutation Nonsense mutation

Description

56. Cell division is regulated through a mechanism known as the ________________________________.

57. True or false: A tumor is a group of cells in which cell division is still entirely controlled. If false,
please correct the statement.

58. Match the following terms to their description: tumor, cancer, cell cycle control system,
proto-oncogene, and oncogene.

A) A tumor that has spread to multiple locations within the body: ____________________________
B) A mutated gene whose product no longer controls the cell cycle: ___________________________
C) A group of cells that has lost control over the cell cycle: _________________________________
D) A gene whose product controls the cell cycle: __________________________________________
E) A mechanism that controls the division of cells: __________________________________________

59. True or false: The spread of cells from a tumor’s original location to a new location is known as
metastasis. If false, please correct the statement.

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60. A patient’s oncologist tells him that the biopsy of his brain tumor shows cell markers that are found only
on lung cells. What has most likely happened?

61. Describe the cancer treatment regimen of “slash, burn, and poison.”

62. List four methods of cancer prevention.

63. True or false: Scientists have not manipulated DNA due to moral and ethical concerns. If false, please
correct the statement.

64. Complete the following table, which compares the methods by which humans manipulate DNA.

Biotechnology DNA Technology Genetic Engineering

Description

65. Match the following terms to their descriptions: DNA ligase, restriction enzyme, plasmid, and
recombinant plasmid.

A) A circular piece of bacterial DNA: ___________________

B) A molecule that cuts DNA at specific sequences: __________________________
C) Bacterial DNA that has been altered through the addition of extra
DNA____________________________
D) A molecule that “pastes” together DNA fragments: ___________________________________
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66. True or false: A restriction site is a sequence of DNA recognized by a specific restriction enzyme. If
false, please correct the statement.

67. Scientists have been able to do which of the following as a result of manipulating DNA?

A) Create genetically modified organisms

B) Identify disease-causing genes
C) Create artificial life forms
D) All of the above have been achieved through the manipulation of DNA.
E) None of the above have been achieved through the manipulation of DNA.

68. An organism’s entire set of DNA is called its _____________________________.

69. True or false: Recombinant DNA contains DNA from at least two sources. If false, please correct the
statement.

70. Match the following terms to their description: genome, recombinant DNA, genomic library, and
nucleic acid probe.

A) A collection of an organism’s entire set of cloned DNA fragments:

______________________________
B) A molecule made of many radioactive subunits: _______________________________________
C) The entire set of genes or DNA that an organism has: _____________________________
D) A molecule of DNA that contains nucleotides from more than one source: ___________________

71. What is the relationship between a genome and a genomic library?

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72. Briefly describe the role of Cas9 during gene editing.

73. ___________________________________________ is an enzyme that can make DNA from mRNA.

74. An organism that has acquired one or more genes as a result of artificial methods is a
______________________.

75. Would a transgenic organism be considered a GMO? Briefly explain your answer.

76. True or false: A scientist can insert recombinant plasmids into crops and create transgenic plants. If
false, please correct the statement.

77. What role does the plasmid have in creating either a transgenic plant or a transgenic animal?

78. A method for quickly and precisely increasing the number of copies of a piece of DNA is called
_____________________________.

79. True or false: In theory, if a criminal leaves behind even a single cell at the crime scene, a scientist can
make many copies of specific DNA sequences from that cell. If false, please correct the statement.

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80. Match the following terms to their descriptions: PCR, thermal cycler, DNA polymerase, and primers.

A) Machine used to increase small amounts of DNA exponentially: _____________________

B) The process by which a small sequence of DNA is significantly increased: ____________________
C) Short sequences of nucleotides that are used to flank the target DNA sequence: __________________
D) Molecule that synthesizes DNA from DNA: _______________________

81. What role does heating and cooling play in PCR?

82. A scientist uses techniques that allow her to determine whether or not DNA left at a crime scene
matches that of a suspect. The scientist used a technique known as _____________________________.

83. True or false: DNA profiling relies on matching entire genomes. If false, please correct the statement.

84. The sequences and locations of STRs are identical from person to person. What actually varies?

85. STR analysis relies on

A) thirteen sites within the human genome.

B) an STR of four nucleotides repeated from 3 to 50 times.
C) PCR to increase the quantity of DNA at the STR sites.
D) All of the above are critical aspects of STR analysis.
E) None of the above are critical aspects of STR analysis.

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86. True or false: Gel electrophoresis is the visualization of DNA using an applied electrical current. If
false, please correct the statement.

87.__________________________ is the study of genomes and their interactions.

88. A method for quickly sequencing a genome is called the ____________________________________.

89. Place the following steps to the shotgun sequencing method in order: DNA sequencing, computer
alignment of overlapping sequences, obtain DNA, upload the DNA into a database, and cut the DNA
with restriction enzymes.

90. Changing a person’s genes to treat an illness is known as ___________________________________.

91. Would gene therapy be an effective treatment for a disease without a genetic component like a staph
infection caused by Methicilin-resistant Staphylococcus aureus (MRSA)?

92. Why does a scientist not simply replace the defective protein with a normal protein? Why must a cell’s
genes be replaced?

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Chapter 7: Darwinian Evolution

1. In 1859, Charles Darwin published On the Origin of Species by Means of Natural Selection. What did
Darwin introduce the scientific community to in this publication?

2. _______ was the first to suggest that species evolved through physical changes that allowed them to
better succeed in their environment.

A) Darwin
B) Lamarck
C) Lyell
D) Aristotle
E) None of the above

3. Which scientist suggested that the Earth is, in fact, very old and gradually changing through slow
processes?

A) Lyell
B) Wallace
C) Darwin
D) Lamarck
E) None of the above

4. True or false: Darwin published his research on evolution only in response to Alfred Russel Wallace
preparing to publish his research on natural selection. If false, please correct the statement.

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 5. List the two main points that Charles Darwin made in the Origin of Species.

6. True or false: Evolution drives natural selection. If false, please correct the statement.

7. Would you expect evolution by natural selection to occur faster in a population that reproduces quickly
or slowly? Briefly explain your answer.

8. What is the unifying theme of biology?

9. True or False: Individuals with traits that make them highly competitive within their environment will
actually have fewer offspring over time. If false, please correct the statement.

10. A common misconception regarding evolution is that organisms evolve. What actually evolves?

A) Organs
B) Populations
C) Molecules
D) Biosphere
E) None of the above

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11. A rancher uses a particular chicken for breeding purposes because, on average, she observed that this
chicken laid more eggs than other chickens. Would this be an example of natural selection or artificial
selection? Briefly explain your answer.

12. A doctor prescribes you an antibiotic for 10 days. You take it for the first 3 days and stop because you
are feeling better. The bacteria that remain

A) would have less resistance to the antibiotic.

B) would be the same as before the antibiotic.
C) would have more resistance to the antibiotic.
D) would have all of the characteristics listed above.
E) All of the above

13. The ordered sequence of fossils found in layers of rock is known as the

14. True or false: Radiometric dating is based on the breakdown of radioactive isotopes over time. If false,
please correct the statement.

15. Fossils can form in a variety of methods. List two ways by which fossils can form.

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16. Other than the fossil record, list three lines of evidence for evolution by natural selection.

17. The distribution of species is known as _______________________________.

18. Complete the following table, which illustrates evidence for evolution.

Biogeography Comparative anatomy Bioinformatics

Description

19. All the variations of all the genes in a population are known as its _____________.

A) microevolution
B) gene pool
C) mutation
D) population
E) None of the above

20. List two factors that influence the diversity of a population’s gene pool.

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21. When genes become more or less frequent within a population over time, this small-scale change is
known as __________________________________________.

22. What can be inferred about the red gene versus the blue gene in the following diagram?

23. Evolution on its smallest scale is called ___________________.

24. True or false: Changes to a population’s gene pool can occur through mutations and geographical
isolation. If false, please correct the statement.

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25. Which of the following best describes Darwinian fitness?

A) The creation of new gene combinations

B) Individuals migrating into and out of an area
C) The ability to produce healthy, viable offspring
D) The change in a population’s gene pool over generations
E) The ability to produce total number of offspring

26. Complete the following table, which illustrates the different mechanisms of evolution.

Bottleneck Sexual
Genetic drift Gene flow effect Founder effect selection

Description

27. True or False: Natural selection is the primary driving force behind evolution. If false, please correct the
statement.

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28. How old is the oldest known fossil?

29. How much time passed between the Earth’s formation and the appearance of the first eukaryotic
organisms?

30. What key evolutionary event occurred 370 million years ago?

31. The ______________________________ are large chunks of the Earth’s crust that float on top of
molten rock.

32. What key event occurred 200,000 years ago?

33. True or false: Microevolution accounts for the creation of new species. If false, please correct the
statement.

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34. Complete the following table, which compares microevolution with macroevolution.

Microevolution Macroevolution

Description

35. ___________________ is the formation of a new species through evolutionary mechanisms.

36. How many mass extinctions has earth suffered?

37. After which mass extinction did mammals take over?

38. When was the largest mass extinction?

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39. A population that is capable of breeding to produce healthy and fertile offspring is known as a
__________________.

40. Complete the following table, which compares the different reproductive barrier mechanisms.

Description with example

Behavioral isolation

Mating time

Habitat isolation

Mechanical incompatibility

Gametic incompatibility

Hybrid weakness

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41. True or false: In its simplest terms, speciation refers to the extinction of a species. If false, please correct
the statement.

42. _________ describes species suddenly appearing and/or disappearing in the fossil record.

A) Graduated
B) Punctuated equilibrium
C) Speciation
D) Allopatric extinction
E) None of the above

43. True or false: Allopatric speciation is where a physical barrier keeps two populations from mating, and
they evolve away from each other over time. If false, please correct the statement.

44. Complete the following table, which illustrates the differences between allopatric and sympatric
speciation.

Allopatric speciation Sympatric speciation

Description

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45. Put the following taxonomic levels in order from larger to smaller categories: phylum, species, genus,
domain, family, kingdom, order, and class.

46. List the three domains.

47. Our scientific name is Homo sapiens. What is our genus? What is our species?

48. A phylogenetic tree really represents a _____________________ about the evolutionary history of a
species.

49. A group of species descended from a common ancestor is known as a ______.

A) speciation
B) phylogenetic tree
C) population
D) clade
E) None of the above

50. The analysis of clades is referred to as _______________________.

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