Question 1

Although DNA is made up of only four different bases, it can encode the information necessary to specify the workings of an entire organism because DNA

Accepted Answer

A)  molecules are extremely long. 
B)  molecules are found in the nucleus. 
C)  is transcribed into RNA and then into proteins with specific functions. 
D)  is eventually translated into proteins, which are made up of 20 different amino acids. 
E)  None of the above 
A)  molecules are extremely long. 
B)  molecules are found in the nucleus. 
C)  is transcribed into RNA and then into proteins with specific functions. 
D)  is eventually translated into proteins, which are made up of 20 different amino acids. 
E)  None of the above

Question 2

Explain the role of Okazaki fragments in the synthesis of the lagging strand.

Accepted Answer

Okazaki fragments are short, newly synth

Question 3

The repetitive sequences at the end of many chromosomes are called _______.

Accepted Answer

The answer of The repetitive sequences at the end of...

Question 4

Watson and Crick's model allowed them to visualize

Accepted Answer

A)  the molecular bonds of DNA. 
B)  the sugar and phosphate component of the DNA molecule's surface. 
C)  how the purines and pyrimidines fit together in a double helix. 
D)  the antiparallel design of two strands of the DNA double helix. 
E)  All of the above 
A)  the molecular bonds of DNA. 
B)  the sugar and phosphate component of the DNA molecule's surface. 
C)  how the purines and pyrimidines fit together in a double helix. 
D)  the antiparallel design of two strands of the DNA double helix. 
E)  All of the above

Question 5

DNA polymerase lengthens a polynucleotide strand by

Accepted Answer

A)  building short DNA fragments and linking them together. 
B)  adding lost DNA sequences to the 3´ end. 
C)  linking purines with pyrimidines. 
D)  covalently linking new nucleotides to a previously existing strand. 
E)  threading the existing DNA through a replication complex. 
A)  building short DNA fragments and linking them together. 
B)  adding lost DNA sequences to the 3´ end. 
C)  linking purines with pyrimidines. 
D)  covalently linking new nucleotides to a previously existing strand. 
E)  threading the existing DNA through a replication complex.

Question 6

Which of the following statements about DNA replication is false?

Accepted Answer

A)  The DNA helix must be unwound for replication to occur. 
B)  The replication complex is made up of proteins. 
C)  The replication complex binds to the origin(s) of replication. 
D)  Primase is a DNA polymerase. 
E)  Single-strand binding proteins are required. 
A)  The DNA helix must be unwound for replication to occur. 
B)  The replication complex is made up of proteins. 
C)  The replication complex binds to the origin(s) of replication. 
D)  Primase is a DNA polymerase. 
E)  Single-strand binding proteins are required.

Question 7

Why is a sliding DNA clamp important in DNA replication?

Accepted Answer

A)  It increases the number of nucleotides polymerized. 
B)  It holds open the two sides of the DNA molecule. 
C)  It slides forward separating additional strands of the DNA molecule. 
D)  It temporarily holds the nucleotides together until phosphodiester bonds can form. 
E)  It unwinds the double helix. 
A)  It increases the number of nucleotides polymerized. 
B)  It holds open the two sides of the DNA molecule. 
C)  It slides forward separating additional strands of the DNA molecule. 
D)  It temporarily holds the nucleotides together until phosphodiester bonds can form. 
E)  It unwinds the double helix.

Question 8

Which of the following statements about DNA structure is false?

Accepted Answer

A)  The 3' end is phosphorylated. 
B)  It is a double-stranded helix. 
C)  It has a uniform diameter. 
D)  It is a right-handed helix. 
E)  It is antiparallel (the two strands run in opposite directions). 
A)  The 3' end is phosphorylated. 
B)  It is a double-stranded helix. 
C)  It has a uniform diameter. 
D)  It is a right-handed helix. 
E)  It is antiparallel (the two strands run in opposite directions).

Question 9

What is the correct order for the following events in excision repair of DNA? (1) DNA polymerase I adds correct bases by 5´ to 3´ replication; (2) damaged bases are recognized; (3) DNA ligase seals the new strand to existing DNA; (4) part of a single strand is excised.

Accepted Answer

A)  1, 2, 3, 4 
B)  2, 1, 3, 4 
C)  2, 4, 1, 3 
D)  3, 4, 2, 1 
E)  4, 2, 3, 1 
A)  1, 2, 3, 4 
B)  2, 1, 3, 4 
C)  2, 4, 1, 3 
D)  3, 4, 2, 1 
E)  4, 2, 3, 1

Question 10

A fundamental requirement for the functioning of genetic material is that it must be

Accepted Answer

A)  conserved among all organisms with very little variation. 
B)  passed intact from one species to another. 
C)  accurately replicated. 
D)  found outside the nucleus. 
E)  replicated accurately over many millions of years of evolution. 
A)  conserved among all organisms with very little variation. 
B)  passed intact from one species to another. 
C)  accurately replicated. 
D)  found outside the nucleus. 
E)  replicated accurately over many millions of years of evolution.

Question 11

To show that DNA is the "transforming principle," Avery, MacLeod, and McCarty showed that DNA could transform nonvirulent strains of pneumococcus. Their hypothesis was strengthened by their demonstration that

Accepted Answer

A)  enzymes that destroy proteins also destroy transforming activity. 
B)  enzymes that destroy nucleic acids also destroy transforming activity. 
C)  enzymes that destroy complex carbohydrates also destroy transforming activity. 
D)  the transforming activity is destroyed by boiling. 
E)  other strains of bacteria also can be transformed successfully. 
A)  enzymes that destroy proteins also destroy transforming activity. 
B)  enzymes that destroy nucleic acids also destroy transforming activity. 
C)  enzymes that destroy complex carbohydrates also destroy transforming activity. 
D)  the transforming activity is destroyed by boiling. 
E)  other strains of bacteria also can be transformed successfully.

Question 12

Griffith's experiments showing the transformation of R strain pneumococcus bacteria to S strain pneumococcus bacteria in the presence of heat-killed S strain bacteria provided evidence that

Accepted Answer

A)  an external factor was affecting the R strain bacteria. 
B)  DNA was definitely the transforming factor. 
C)  S strain bacteria could be reactivated after heat killing. 
D)  S strain bacteria required special genes to be pathogenic. 
E)  All of the above 
A)  an external factor was affecting the R strain bacteria. 
B)  DNA was definitely the transforming factor. 
C)  S strain bacteria could be reactivated after heat killing. 
D)  S strain bacteria required special genes to be pathogenic. 
E)  All of the above

Question 13

In Griffith's experiments, when heat-killed S strain pneumococci were injected into a mouse along with live R strain pneumococci,

Accepted Answer

A)  DNA from the live R was taken up by the heat-killed S, converting the latter to R and killing the mouse. 
B)  DNA from the heat-killed S was taken up by the live R, converting the latter to S and killing the mouse. 
C)  proteins released from the heat-killed S killed the mouse. 
D)  RNA from the heat-killed S was translated into proteins that killed the mouse. 
E)  there was no result. 
A)  DNA from the live R was taken up by the heat-killed S, converting the latter to R and killing the mouse. 
B)  DNA from the heat-killed S was taken up by the live R, converting the latter to S and killing the mouse. 
C)  proteins released from the heat-killed S killed the mouse. 
D)  RNA from the heat-killed S was translated into proteins that killed the mouse. 
E)  there was no result.

Question 14

In organisms that contain circular DNA,

Accepted Answer

A)  there are often multiple origins of replication. 
B)  DNA replication is conservative. 
C)  the replication complex moves down the DNA like a locomotive on a track. 
D)  the duplicated DNA molecules are interlocked. 
E)  DNA replication is slow. 
A)  there are often multiple origins of replication. 
B)  DNA replication is conservative. 
C)  the replication complex moves down the DNA like a locomotive on a track. 
D)  the duplicated DNA molecules are interlocked. 
E)  DNA replication is slow.

Question 15

The DNA isolated from a newly discovered virus is found to be 32 percent A, 18 percent C, 18 percent G, and 32 percent T. The base composition of the complementary DNA would be _______ percent A, _______ percent C, _______ percent G, and _______ percent T.

Accepted Answer

A)  32; 17; 32; 19 
B)  19; 32; 17; 32 
C)  17; 32; 32; 19 
D)  25; 25; 25; 25 
E)  32; 18; 18; 32 
A)  32; 17; 32; 19 
B)  19; 32; 17; 32 
C)  17; 32; 32; 19 
D)  25; 25; 25; 25 
E)  32; 18; 18; 32

Question 16

Griffith's experiment with pneumococcus demonstrated that

Accepted Answer

A)  smooth bacteria can survive heating. 
B)  DNA, not protein, is the genetic molecule. 
C)  materials from dead organisms can affect and change living organisms. 
D)  nonliving viruses can change living cells. 
E)  None of the above 
A)  smooth bacteria can survive heating. 
B)  DNA, not protein, is the genetic molecule. 
C)  materials from dead organisms can affect and change living organisms. 
D)  nonliving viruses can change living cells. 
E)  None of the above

Question 17

In the 1920s, circumstantial evidence indicated that DNA was the genetic material. Which of the following experiments led to the acceptance of this hypothesis?

Accepted Answer

A)  Griffith's experiments with Streptococcus pneumoniae 
B)  Avery, MacLeod, and McCarty's work with isolating the transforming principle 
C)  Hershey and Chase's experiments with viruses and radioisotopes 
D)  Franklin's X-ray crystallography 
E)  a, b, and c 
A)  Griffith's experiments with Streptococcus pneumoniae 
B)  Avery, MacLeod, and McCarty's work with isolating the transforming principle 
C)  Hershey and Chase's experiments with viruses and radioisotopes 
D)  Franklin's X-ray crystallography 
E)  a, b, and c

Question 18

Thirty percent of the bases in a sample of DNA extracted from eukaryotic cells are adenine. What percentage of cytosine is present in this DNA?

Accepted Answer

A)  10 percent 
B)  20 percent 
C)  30 percent 
D)  40 percent 
E)  50 percent 
A)  10 percent 
B)  20 percent 
C)  30 percent 
D)  40 percent 
E)  50 percent

Question 19

Explain the difference between conservative and semiconservative models of DNA replication. What results supported the semiconservative model? What would the results have looked like if the conservative model of DNA replication had been accurate? Are there any other potential hypotheses?

Accepted Answer

In the conservative model of DNA replica

Question 20

Hershey and Chase used radioactive 35S and 32P in experiments to provide evidence that DNA is the genetic material. These experiments pointed to DNA because

Accepted Answer

A)  progeny viruses retained 32P but not 35S. 
B)  the presence of 32P in progeny viruses indicated that DNA was passed on. 
C)  the absence of 35S in progeny viruses indicated that proteins were not passed on. 
D)  32P indicated where the DNA label was localized. 
E)  All of the above 
A)  progeny viruses retained 32P but not 35S. 
B)  the presence of 32P in progeny viruses indicated that DNA was passed on. 
C)  the absence of 35S in progeny viruses indicated that proteins were not passed on. 
D)  32P indicated where the DNA label was localized. 
E)  All of the above

Exam 13: Dna and Its Role in Heredity

Although DNA is made up of only four different bases, it can encode the information necessary to specify the workings of an entire organism because DNA

Explain the role of Okazaki fragments in the synthesis of the lagging strand.

The repetitive sequences at the end of many chromosomes are called _______.

Watson and Crick's model allowed them to visualize

DNA polymerase lengthens a polynucleotide strand by

Which of the following statements about DNA replication is false?

Why is a sliding DNA clamp important in DNA replication?

Which of the following statements about DNA structure is false?

What is the correct order for the following events in excision repair of DNA? (1) DNA polymerase I adds correct bases by 5´ to 3´ replication; (2) damaged bases are recognized; (3) DNA ligase seals the new strand to existing DNA; (4) part of a single strand is excised.

A fundamental requirement for the functioning of genetic material is that it must be

To show that DNA is the "transforming principle," Avery, MacLeod, and McCarty showed that DNA could transform nonvirulent strains of pneumococcus. Their hypothesis was strengthened by their demonstration that

Griffith's experiments showing the transformation of R strain pneumococcus bacteria to S strain pneumococcus bacteria in the presence of heat-killed S strain bacteria provided evidence that

In Griffith's experiments, when heat-killed S strain pneumococci were injected into a mouse along with live R strain pneumococci,

In organisms that contain circular DNA,

The DNA isolated from a newly discovered virus is found to be 32 percent A, 18 percent C, 18 percent G, and 32 percent T. The base composition of the complementary DNA would be _______ percent A, _______ percent C, _______ percent G, and _______ percent T.

Griffith's experiment with pneumococcus demonstrated that

In the 1920s, circumstantial evidence indicated that DNA was the genetic material. Which of the following experiments led to the acceptance of this hypothesis?

Thirty percent of the bases in a sample of DNA extracted from eukaryotic cells are adenine. What percentage of cytosine is present in this DNA?

Explain the difference between conservative and semiconservative models of DNA replication. What results supported the semiconservative model? What would the results have looked like if the conservative model of DNA replication had been accurate? Are there any other potential hypotheses?

Hershey and Chase used radioactive 35S and 32P in experiments to provide evidence that DNA is the genetic material. These experiments pointed to DNA because

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The DNA isolated from a newly discovered virus is found to be 32 percent A, 18 percent C, 18 percent G, and 32 percent T. The base composition of the complementary DNA would be ___ percent A, _ percent C, _ percent G, and ___ percent T.

Hershey and Chase used radioactive ³⁵S and ³²P in experiments to provide evidence that DNA is the genetic material. These experiments pointed to DNA because