Question 1

The enzyme _______ catalyzes the addition of nucleotides to a growing strand of DNA.

Accepted Answer

The answer of The enzyme _______ catalyzes the addition of...

Question 2

If Meselson and Stahl had observed one intermediate, slightly smeared band after growing bacteria in the presence of 15N for one generation, and then after two generations in 14N again had found one slightly smeared band, they would most likely have concluded that DNA replicates

Accepted Answer

A)  semiconservatively. 
B)  conservatively. 
C)  semidiscontinuously. 
D)  dispersively. 
E)  semicontinuously. 
A)  semiconservatively. 
B)  conservatively. 
C)  semidiscontinuously. 
D)  dispersively. 
E)  semicontinuously.

Question 3

Explain the method used by Meselson and Stahl in their experiments to discriminate between template DNA and newly synthesized DNA using density gradient.

Accepted Answer

Meselson and Stahl labeled the DNA using

Question 4

The energy necessary for making a DNA molecule comes directly from

Accepted Answer

A)  sugar. 
B)  ATP. 
C)  the release of phosphates. 
D)  NADPH. 
E)  NADH. 
A)  sugar. 
B)  ATP. 
C)  the release of phosphates. 
D)  NADPH. 
E)  NADH.

Question 5

The rules formulated by Erwin Chargaff state that

Accepted Answer

A)  A = T and G = C in any sample of DNA. 
B)  A = C and G = T in any sample of DNA. 
C)  A = G and C = T in any sample of DNA. 
D)  A = C = G = T in any sample of DNA. 
E)  the base composition of DNA is completely variable. 
A)  A = T and G = C in any sample of DNA. 
B)  A = C and G = T in any sample of DNA. 
C)  A = G and C = T in any sample of DNA. 
D)  A = C = G = T in any sample of DNA. 
E)  the base composition of DNA is completely variable.

Question 6

Which statement about DNA replication is false?

Accepted Answer

A)  Okazaki fragments are synthesized as parts of the leading strand. 
B)  Replication forks represent areas of active DNA synthesis on the chromosomes. 
C)  Error rates for DNA replication are reduced by proofreading of the DNA polymerase. 
D)  Ligases and polymerases function in the vicinity of replication forks. 
E)  The sliding clamp increases the rate of DNA synthesis. 
A)  Okazaki fragments are synthesized as parts of the leading strand. 
B)  Replication forks represent areas of active DNA synthesis on the chromosomes. 
C)  Error rates for DNA replication are reduced by proofreading of the DNA polymerase. 
D)  Ligases and polymerases function in the vicinity of replication forks. 
E)  The sliding clamp increases the rate of DNA synthesis.

Question 7

A researcher studies normal human fibroblast cells.They can be maintained in culture but die off after about 30 cell generations.Unexpectedly, a colony of cells continues to survive and divide past 30 generations.Which scenario is most likely true for these cells?

Accepted Answer

A)  DNA polymerase is constantly active. 
B)  The mismatch repair system is extra efficient. 
C)  The telomerase gene is being expressed. 
D)  Primase is able to extend the telomeres. 
E)  The cells do not need the ends of their chromosomes. 
A)  DNA polymerase is constantly active. 
B)  The mismatch repair system is extra efficient. 
C)  The telomerase gene is being expressed. 
D)  Primase is able to extend the telomeres. 
E)  The cells do not need the ends of their chromosomes.

Question 8

Refer to the figure.   Which letter represents the leading strand?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  E 
A)  A 
B)  B 
C)  C 
D)  D 
E)  E

Question 9

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)  nearly 100 percent 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)  nearly 100 percent accurately replicated. 
D)  found outside the nucleus. 
E)  replicated accurately over many millions of years of evolution.

Question 10

The enzyme that unwinds the DNA prior to replication is called

Accepted Answer

A)  DNA polymerase III. 
B)  DNA ligase. 
C)  single-stranded DNA binding protein. 
D)  primase. 
E)  helicase. 
A)  DNA polymerase III. 
B)  DNA ligase. 
C)  single-stranded DNA binding protein. 
D)  primase. 
E)  helicase.

Question 11

New DNA molecules can be synthesized in a test tube containing _______ as substrate.

Accepted Answer

A)  deoxyribose nucleoside monophosphates 
B)  deoxyribose nucleoside diphosphates 
C)  deoxyribose nucleoside triphosphates 
D)  deoxyribose nucleotide diphosphates 
E)  deoxyribose nucleotide triphosphates 
A)  deoxyribose nucleoside monophosphates 
B)  deoxyribose nucleoside diphosphates 
C)  deoxyribose nucleoside triphosphates 
D)  deoxyribose nucleotide diphosphates 
E)  deoxyribose nucleotide triphosphates

Question 12

The bases from DNA isolated from a newly discovered single-stranded virus are found to be 32 percent A, 18 percent C, 18 percent G, and 32 percent T.During replication, this DNA forms a complementary strand.The bases 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 13

Chargaff's rule states that

Accepted Answer

A)  DNA must be replicated before a cell can divide. 
B)  a virus can enter a cell only without its protein coat. 
C)  only protein from the infecting phage can also be detected in progeny phages. 
D)  only nucleic acids enter the cell during infection. 
E)  the amount of cytosine equals the amount of guanine. 
A)  DNA must be replicated before a cell can divide. 
B)  a virus can enter a cell only without its protein coat. 
C)  only protein from the infecting phage can also be detected in progeny phages. 
D)  only nucleic acids enter the cell during infection. 
E)  the amount of cytosine equals the amount of guanine.

Question 14

DNA polymerases catalyze many polymerizations in a row each time they bind to a DNA molecule.Therefore, DNA polymerases are said to be _______.

Accepted Answer

The answer of DNA polymerases catalyze many polymerizations in a...

Question 15

DNA polymerase lengthens a polynucleotide strand in a DNA molecule by

Accepted Answer

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

Question 16

The Meselson-Stahl experiment showed that DNA

Accepted Answer

A)  replication is conservative. 
B)  is synthesized in only one direction. 
C)  replication is dispersive. 
D)  replication is semiconservative. 
E)  exists as a double helix. 
A)  replication is conservative. 
B)  is synthesized in only one direction. 
C)  replication is dispersive. 
D)  replication is semiconservative. 
E)  exists as a double helix.

Question 17

The expression of the enzyme _______ is largely restricted to stem cells and gametes.However, it is expressed in 90 percent of human cancers and may be responsible for their ability to survive continuous division.

Accepted Answer

The answer of The expression of the enzyme _______ is...

Question 18

If _______ was nonfunctional, then DNA polymerase could not replicate the 3ʹ-to-5ʹ strand of template DNA.

Accepted Answer

The answer of If _______ was nonfunctional, then DNA polymerase...

Question 19

In their experiment, Hershey and Chase tracked whether proteins or DNA entered the nucleus by using different _______ to label the proteins and DNA.

Accepted Answer

The answer of In their experiment, Hershey and Chase tracked...

Question 20

An alien DNA-like molecule is isolated from the frozen remains of a life form found beneath the Martian polar ice caps.In this sample, for every base designated Q, there is twice that amount of base R; for every base Z, there is twice that amount of base S.If the molecule contains 33.33 percent S, you expect to find _______ percent Z.

Accepted Answer

A)  8.33 
B)  16.67 
C)  50 
D)  66.66 
E)  66.67 
A)  8.33 
B)  16.67 
C)  50 
D)  66.66 
E)  66.67

Exam 13: Dna and Its Role in Heredity

The enzyme _______ catalyzes the addition of nucleotides to a growing strand of DNA.

If Meselson and Stahl had observed one intermediate, slightly smeared band after growing bacteria in the presence of 15N for one generation, and then after two generations in 14N again had found one slightly smeared band, they would most likely have concluded that DNA replicates

Explain the method used by Meselson and Stahl in their experiments to discriminate between template DNA and newly synthesized DNA using density gradient.

The energy necessary for making a DNA molecule comes directly from

The rules formulated by Erwin Chargaff state that

Which statement about DNA replication is false?

A researcher studies normal human fibroblast cells.They can be maintained in culture but die off after about 30 cell generations.Unexpectedly, a colony of cells continues to survive and divide past 30 generations.Which scenario is most likely true for these cells?

Refer to the figure. Which letter represents the leading strand?

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

The enzyme that unwinds the DNA prior to replication is called

New DNA molecules can be synthesized in a test tube containing _______ as substrate.

Chargaff's rule states that

DNA polymerases catalyze many polymerizations in a row each time they bind to a DNA molecule.Therefore, DNA polymerases are said to be _______.

DNA polymerase lengthens a polynucleotide strand in a DNA molecule by

The Meselson-Stahl experiment showed that DNA

The expression of the enzyme _______ is largely restricted to stem cells and gametes.However, it is expressed in 90 percent of human cancers and may be responsible for their ability to survive continuous division.

If _______ was nonfunctional, then DNA polymerase could not replicate the 3ʹ-to-5ʹ strand of template DNA.

In their experiment, Hershey and Chase tracked whether proteins or DNA entered the nucleus by using different _______ to label the proteins and DNA.

Studying Life

Small Molecules and the Chemistry of Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Communication and Multicellularity

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinant Dna and Biotechnology

Mechanisms of Evolution

Reconstructing and Using Phylogenies

Speciation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

The Evolution and Diversity of Fungi

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

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Immunology: Animal Defense Systems

Animal Reproduction

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Neurons, Glia, and Nervous Systems

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The Mammalian Nervous System: Structure and Higher Functions

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Salt and Water Balance and Nitrogen Excretion

Animal Behavior

The Physical Environment and Biogeography of Life

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A Changing Biosphere

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If Meselson and Stahl had observed one intermediate, slightly smeared band after growing bacteria in the presence of ¹⁵N for one generation, and then after two generations in ¹⁴N again had found one slightly smeared band, they would most likely have concluded that DNA replicates