Question 1

In Figure 15.2, which is the template strand?

Accepted Answer

A)  a 
B)  b 
C)  c 
D)  d 
A)  a 
B)  b 
C)  c 
D)  d

Question 2

What provides the energy for the polymerization reactions in DNA synthesis?

Accepted Answer

A)  breaking the hydrogen bonds between complementary DNA strands 
B)  ATP 
C)  DNA polymerase 
D)  the deoxyribonucleotide triphosphate substrates 
A)  breaking the hydrogen bonds between complementary DNA strands 
B)  ATP 
C)  DNA polymerase 
D)  the deoxyribonucleotide triphosphate substrates

Question 3

DNA is synthesized through a process known as

Accepted Answer

A)  conservative replication. 
B)  dispersive replication. 
C)  semiconservative replication. 
D)  transcription. 
A)  conservative replication. 
B)  dispersive replication. 
C)  semiconservative replication. 
D)  transcription.

Question 4

Researchers found E. coli that had mutation rates 100 times higher than normal. What is a possible explanation for these results?

Accepted Answer

A)  The proofreading mechanism of DNA polymerase was not working properly. 
B)  There were one or more mismatches in the RNA primer. 
C)  The DNA polymerase was unable to add bases to the 3' end of the growing nucleic acid chain. 
D)  The single- stranded binding proteins were malfunctioning. 
A)  The proofreading mechanism of DNA polymerase was not working properly. 
B)  There were one or more mismatches in the RNA primer. 
C)  The DNA polymerase was unable to add bases to the 3' end of the growing nucleic acid chain. 
D)  The single- stranded binding proteins were malfunctioning.

Question 5

Telomere shortening puts a limit on the number of times a cell can divide. Research has shown that telomerase can extend the life span of cultured human cells. How might adding telomerase affect cellular aging?

Accepted Answer

A)  Telomerase shortens telomeres, which delays cellular aging. 
B)  Telomerase will speed up the rate of cell proliferation. 
C)  Telomerase would have no effect on cellular aging. 
D)  Telomerase would decrease the rate of DNA replication. 
E)  Telomerase eliminates telomere shortening and retards aging. 
A)  Telomerase shortens telomeres, which delays cellular aging. 
B)  Telomerase will speed up the rate of cell proliferation. 
C)  Telomerase would have no effect on cellular aging. 
D)  Telomerase would decrease the rate of DNA replication. 
E)  Telomerase eliminates telomere shortening and retards aging.

Question 6

Which of the following cells do not have active telomerase activity?

Accepted Answer

A)  most normal somatic cells 
B)  most cancer cells 
C)  most normal germ cells 
A)  most normal somatic cells 
B)  most cancer cells 
C)  most normal germ cells

Question 7

What is a major difference between eukaryotic DNA replication and prokaryotic DNA replication?

Accepted Answer

A)  DNA polymerases of prokaryotes can add nucleotides to both 3' and 5' ends of DNA strands, while those of eukaryotes function only in the 5'-3' direction. 
B)  DNA polymerase III of eukaryotes has both endonuclease and exonuclease activity, while that of prokaryotes has only exonuclease activity. 
C)  Prokaryotic replication does not require a primer. 
D)  Prokaryotic chromosomes have a single origin of replication, while eukaryotic chromosomes have multiple origins of replication. 
A)  DNA polymerases of prokaryotes can add nucleotides to both 3' and 5' ends of DNA strands, while those of eukaryotes function only in the 5'-3' direction. 
B)  DNA polymerase III of eukaryotes has both endonuclease and exonuclease activity, while that of prokaryotes has only exonuclease activity. 
C)  Prokaryotic replication does not require a primer. 
D)  Prokaryotic chromosomes have a single origin of replication, while eukaryotic chromosomes have multiple origins of replication.

Question 8

Watson and Crick elucidated the structure of DNA in 1953. Their research built on and helped explain the findings of other scientists, including

Accepted Answer

A)  Scientists who recognized that a nucleotide consisted of a sugar, a phosphate, and a nitrogen- containing base. 
B)  X- ray diffraction studies by Rosalind Franklin and Maurice Wilkins. 
C)  Chargaff's rules: C = G and T = A. 
D)  All of the above were important considerations in the elucidation of the structure of DNA. 
A)  Scientists who recognized that a nucleotide consisted of a sugar, a phosphate, and a nitrogen- containing base. 
B)  X- ray diffraction studies by Rosalind Franklin and Maurice Wilkins. 
C)  Chargaff's rules: C = G and T = A. 
D)  All of the above were important considerations in the elucidation of the structure of DNA.

Question 9

In the polymerization of DNA, a phosphodiester bond is formed between a phosphate group of the nucleotide being added and of the last nucleotide in the polymer.

Accepted Answer

A)  a nitrogen from the nitrogen- containing base 
B)  C6 
C)  the 3' OH 
D)  ATP 
A)  a nitrogen from the nitrogen- containing base 
B)  C6 
C)  the 3' OH 
D)  ATP

Question 10

What is a telomere?

Accepted Answer

A)  the ends of linear chromosomes 
B)  the reorganization of the cell nucleus that takes place during telophase 
C)  the site of origin of DNA replication 
D)  the mechanism that holds two sister chromatids together 
A)  the ends of linear chromosomes 
B)  the reorganization of the cell nucleus that takes place during telophase 
C)  the site of origin of DNA replication 
D)  the mechanism that holds two sister chromatids together

Question 11

Hershey and Chase set out to determine what molecule served as the unit of inheritance. They completed a series of transduction experiments in which E. coli was infected by a T2 virus. Which molecular component of the T2 virus actually ended up inside the cell?

Accepted Answer

A)  DNA 
B)  lipid 
C)  protein 
D)  carbohydrate 
A)  DNA 
B)  lipid 
C)  protein 
D)  carbohydrate

Question 12

Which of the following are important in reducing the errors in DNA replication in E. coli organisms?

Accepted Answer

A)  mismatch repair 
B)  nucleotide excision repair 
C)  proofreading activity of the epsilon subunit of DNA polymerase III 
D)  All of the above minimize errors in DNA replication in E. coli. 
A)  mismatch repair 
B)  nucleotide excision repair 
C)  proofreading activity of the epsilon subunit of DNA polymerase III 
D)  All of the above minimize errors in DNA replication in E. coli.

Question 13

Figure 15.2
-Identify the lagging strand in Figure 15.2.

Accepted Answer

A)  a 
B)  b 
C)  c 
D)  d 
A)  a 
B)  b 
C)  c 
D)  d

Question 14

Figure 15.3
-Refer to Figure 15.3. Which structure is responsible for stabilizing DNA in its single- stranded form?

Accepted Answer

The answer of   Figure 15.3
-Refer to Figure 15.3....

Question 15

If DNA repair mechanisms fail, what is the result?

Accepted Answer

A)  cancer 
B)  a mutation 
C)  a defective enzyme 
D)  All of the above can result from the failure of DNA repair mechanisms. 
A)  cancer 
B)  a mutation 
C)  a defective enzyme 
D)  All of the above can result from the failure of DNA repair mechanisms.

Question 16

What is the difference between the leading strand and the lagging strand in DNA replication?

Accepted Answer

A)  The leading strand is synthesized in the 3'-5' direction in a discontinuous fashion, while the lagging strand is synthesized in the 5'-3' direction in a continuous fashion. 
B)  The leading strand is synthesized continuously in the 5'-3' direction, while the lagging strand is synthesized discontinuously in the 5'-3' direction. 
C)  The leading strand requires an RNA primer, whereas the lagging strand does not. 
D)  There are different DNA polymerases involved in elongation of the leading strand and the lagging strand. 
A)  The leading strand is synthesized in the 3'-5' direction in a discontinuous fashion, while the lagging strand is synthesized in the 5'-3' direction in a continuous fashion. 
B)  The leading strand is synthesized continuously in the 5'-3' direction, while the lagging strand is synthesized discontinuously in the 5'-3' direction. 
C)  The leading strand requires an RNA primer, whereas the lagging strand does not. 
D)  There are different DNA polymerases involved in elongation of the leading strand and the lagging strand.

Question 17

Bodnar et al. 1998) used telomerase to extend the life span of normal human cells. Telomere shortening puts a limit on the number of times a cell can divide. How might adding telomerase affect cellular aging?

Accepted Answer

A)  Telomerase shortens telomeres and thus delays cellular aging. 
B)  Telomerase ensures that the ends of the chromosomes are accurately replicated and eliminates telomere shortening. 
C)  Telomerase will speed up the rate of cell proliferation. 
D)  Telomerase would have no effect on cellular aging. 
A)  Telomerase shortens telomeres and thus delays cellular aging. 
B)  Telomerase ensures that the ends of the chromosomes are accurately replicated and eliminates telomere shortening. 
C)  Telomerase will speed up the rate of cell proliferation. 
D)  Telomerase would have no effect on cellular aging.

Question 18

Recent studies have shown that xeroderma pigmentosum an error in the nucleotide excision repair process) can result from mutations in one of seven genes. What can you infer from this finding?

Accepted Answer

A)  These mutations have resulted from translocation of gene segments. 
B)  These seven genes are the most easily damaged by ultraviolet light. 
C)  There are several enzymes involved in the nucleotide excision repair process. 
D)  There are seven genes that produce the same protein. 
A)  These mutations have resulted from translocation of gene segments. 
B)  These seven genes are the most easily damaged by ultraviolet light. 
C)  There are several enzymes involved in the nucleotide excision repair process. 
D)  There are seven genes that produce the same protein.

Question 19

At a specific area of a chromosome, the following sequence of nucleotides is present where the chain opens to fo replication fork:
3' C C T A G G C T G C A A T C C 5'
An RNA primer is formed starting at the underlined T T) of the template. Which of the following represents the primer sequence?

Accepted Answer

A)  5' G C C T A G G 3' 
B)  5' A C G T T A G G 3' 
C)  3' G C C T A G G 5' 
D)  5' G C C U A G G 3' 
E)  5' A C G U U A G G 3' 
A)  5' G C C T A G G 3' 
B)  5' A C G T T A G G 3' 
C)  3' G C C T A G G 5' 
D)  5' G C C U A G G 3' 
E)  5' A C G U U A G G 3'

Exam 15: Dna and the Gene: Synthesis and Repair

In Figure 15.2, which is the template strand?

What provides the energy for the polymerization reactions in DNA synthesis?

DNA is synthesized through a process known as

Researchers found E. coli that had mutation rates 100 times higher than normal. What is a possible explanation for these results?

Telomere shortening puts a limit on the number of times a cell can divide. Research has shown that telomerase can extend the life span of cultured human cells. How might adding telomerase affect cellular aging?

Which of the following cells do not have active telomerase activity?

What is a major difference between eukaryotic DNA replication and prokaryotic DNA replication?

Watson and Crick elucidated the structure of DNA in 1953. Their research built on and helped explain the findings of other scientists, including

In the polymerization of DNA, a phosphodiester bond is formed between a phosphate group of the nucleotide being added and of the last nucleotide in the polymer.

What is a telomere?

Hershey and Chase set out to determine what molecule served as the unit of inheritance. They completed a series of transduction experiments in which E. coli was infected by a T2 virus. Which molecular component of the T2 virus actually ended up inside the cell?

Which of the following are important in reducing the errors in DNA replication in E. coli organisms?

Figure 15.2 -Identify the lagging strand in Figure 15.2.

Figure 15.3 -Refer to Figure 15.3. Which structure is responsible for stabilizing DNA in its single- stranded form?

If DNA repair mechanisms fail, what is the result?

What is the difference between the leading strand and the lagging strand in DNA replication?

Bodnar et al. 1998) used telomerase to extend the life span of normal human cells. Telomere shortening puts a limit on the number of times a cell can divide. How might adding telomerase affect cellular aging?

Recent studies have shown that xeroderma pigmentosum an error in the nucleotide excision repair process) can result from mutations in one of seven genes. What can you infer from this finding?

At a specific area of a chromosome, the following sequence of nucleotides is present where the chain opens to fo replication fork: 3' C C T A G G C T G C A A T C C 5' An RNA primer is formed starting at the underlined T T) of the template. Which of the following represents the primer sequence?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Gene Structure and Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioural Ecology

Population Ecology

Community Ecology

Ecosystems and Global Ecology

Biodiversity and Conservation Biology

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