MOLECULAR BIOLOGY OF THE CELL, SIXTH EDITION q q q q q q
CHAPTER 1: CELLS AND GENOMES q q q q q
© Garland Science 2015
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1 Scientists discover more than ten thousand new species of living organisms every year.
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q What is shared between all of these organisms?
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A. They are made of cells, whose nuclei enclose their DNA.
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B. They obtain their energy from sunlight.
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C. They produce and use adenosine triphosphate (ATP).
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D. Their genome contains at least 1000 genes.
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E. All of the above.
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2 All cells …
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A. have membrane transport proteins.
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B. synthesize proteins on the ribosome. q q q q
C. replicate their genome by DNA polymerization. q q q q q
D. transcribe their genetic information by RNA polymerization.
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E. All of the above. q q q
3 Imagine a segment of DNA (within a gene) encoding a certain amount of information in
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its nucleotide sequence. When this segment is fully transcribed into mRNA and then translated
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into protein, in general, …
q q q q q
A. the protein sequence would carry more information compared to the DNA and mRNA
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sequences, because its alphabet has 20 letters.
q q q q q q q
q B. the protein sequence would carry less information compared to the DNA and mRNA
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sequences, because several codons can correspond to one amino acid.
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C. the amount of information in the mRNA sequence is lower, because the mRNA has
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been transcribed using only one of the DNA strands as the template.
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D. the amount of information in the mRNA sequence is higher, because several mRNA
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molecules can be transcribed from one DNA molecule.
q q q q q q q q
4 Which of the following processes that happens inside a cell DOES NOT normally require
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consumption of free energy by the cell?
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, A. Replication of the genetic material q q q q
B. Import of nutrients from the environment
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C. Diffusion of small molecules within the cell q q q q q q
D. Regulation of gene expression q q q
E. Synthesis of enzymes that catalyze cellular reactions q q q q q q
5 Which of the following would you N OT expect to find in a bacterial cell?
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A. Swimming using flagella q q
B. Having a cell wall around the plasma membrane q q q q q q q
q C. ATP production in mitochondria
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D. Protein production on the ribosome q q q q
E. Sexual exchange of DNA with other bacteriaq q q q q q
6 To trace family relationships between distantly related organisms such as humans, algae,
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bacteria, and archaea, one should compare their genomes in regions …
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A. that evolve rapidly.
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B. that have a higher mutation rate.
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C. that code for proteins.
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D. where mutations are hardly tolerated.
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E. where most mutations are selectively neutral.
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7 Laboratory strains of the model organism Escherichia coli that are resistant to antibiotics
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are very often used in research laboratories as well as in the biotechnology industry. If cultures
q q q q q q q q q q q q q q q q
q of such bacteria were allowed to contaminate the environment uncontrollably, it is possible that
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qat some point, pathogenic bacteria such as Neisseria meningitidis (which causes meningitis and
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can cause death, especially in children) could acquire the same antibiotic-resistance gene,
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q causing a meningitis outbreak that is difficult to treat. In this scenario, which of the following
q q q q q q q q q q q q q q q
mechanisms is a more likely source of the antibiotic-resistance gene in N. meningitidis?
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A. Random new gene generation q q q
B. Intragenic mutation q
C. Gene duplication q
D. DNA segment shuffling q q
E. Horizontal gene transfer q q
8 A virus …
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A. is a type of cell.
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, B. has genetic material made of proteins.
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C. can only infect a single host species.
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D. can act as a vector for gene transfer.
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E. cannot persist in its host for more than one cell generation.
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9 Which of the following does NOT typically involve horizontal gene transfer?
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A. Sexual reproduction in humans q q q
B. Bacteriophage infection of bacteria q q q
C. The evolutionary history of the eukaryotic cell
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D. The accidental duplication of a small region of a bacterial chromosome followed by
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cell division
q q
E. Introduction of plasmids into bacteria in a laboratory q q q q q q q
10 Gene duplication can give rise to homologous genes that are part of gene families. For
q q q q q q q q q q q q q q
example, there are six actin genes in the genome of most mammalian species. In humans, the
q q q q q q q q q q q q q q q q
ACTB gene, which encodes a cytoskeletal actin, is expressed ubiquitously, while ACTC1 is
q q q q q q q q q q q q q
expressed mainly in cardiac cells. Although bacteria lack the eukaryotic cytoskeletal
q q q q q q q q q q q
qorganization, the bacterial MreB gene bears recognizable sequence similarity to mammalian
q q q q q q q q q q
actin genes and codes for a protein that is similar to actin in structure and function. Which of the
q q q q q q q q q q q q q q q q q q q
following statements is true about these genes?
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A. ACTB is homologous to ACTC1 but not to MreB.
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B. ACTB is orthologous to ACTC1 but not to MreB.
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C. ACTB is paralogous to ACTC1 but not to MreB.
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D. MreB is orthologous to ACTB but not to ACTC1.
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E. ACTB is paralogous to both ACTC1 and MreB.
q q q q q q q
11 Out of nearly 5000 protein-coding gene families, there is a set of nearly 300 conserved
q q q q q q q q q q q q q q
gene families that are found in species from all domains of life. When one looks at the general
q q q q q q q q q q q q q q q q q q
q functions assigned to these gene families, it is found that …
q q q q q q q q q q
A. the majority of them function in cell-to-cell signaling.
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B. the majority of them are poorly characterized.
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C. more than one-third of them are involved in translation or amino acid transport
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and m etabolism.
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D. more than one-half of the shared families are involved in DNA replication
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and transcription.
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E. Nearly all of them are involved in energy production and carbohydrate metabolism.
q q q q q q q q q q q
, 12 Which of the following is true regarding Escherichia coli?
q q q q q q q q
A. Most of our understanding about mitosis comes from studies on this model organism.
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B. It is a rod-shaped bacterium that can only grow in the gut of humans and
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other vertebrates.
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C. Two strains of E. coli can differ by up to 0.1% in their genomes.
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D . E. coli strain K-12 encodes about 4300 proteins.
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E. The E. coli (strain K-12) genome is about 430 million nucleotide pairs long.
q q q q q q q q q q q q q
13 Which of the following is NOT true regarding the tree of life?
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A. Most bacteria and archaea have 1000 to 6000 genes in their genomes.
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B. Eukaryotes are more similar to archaea than to bacteria with respect to the
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proteins that act on their DNA.
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C. Most bacteria and archaea have genome sizes between one and ten million nucleotide
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pairs, whereas eukaryotic genomes can be millions of times larger.
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D. Archaeal species were thought to belong to the eukaryotic world before
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sequence analysis placed them in a separate domain of life.
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E. Photosynthetic bacteria are thought to be the ancestors of the eukaryotic chloroplasts. q q q q q q q q q q q
14 A mutation in the cdc28 gene in the budding yeast Saccharomyces cerevisiae causes cell-
q q q q q q q q q q q q q
cycle arrest, giving rise to unbudded cells that look like “dumbbells.” Treatment of wild-type
q q q q q q q q q q q q q q
cells with nocodazole, a drug that destabilizes some cytoskeletal polymers, leads to a similar
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phenotype. Based only on these observations, which statement is true regarding cdc28?
q q q q q q q q q q q q
A. cdc28 codes for a master regulatory kinase that phosphorylates other proteins.
q q q q q q q q q q
B. Nocodazole binds to the protein coded by the cdc28 gene.q q q q q q q q q
C. The product of the cdc28 gene is responsible for resistance to nocodazole.
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D. The product of the cdc28 gene is involved in cell cycle regulation.
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E. The product of cdc28 destabilizes the same cytoskeletal polymers that
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qnocodazole also destabilizes. q q
15 Which of the following structures is exclusively found in eukaryotic cells?
q q q q q q q q q q
A. Plasma membrane q
B. Cell wall q
C. Chromosome
D. Ribosome
E. Lysosome
CHAPTER 1: CELLS AND GENOMES q q q q q
© Garland Science 2015
q q q
1 Scientists discover more than ten thousand new species of living organisms every year.
q q q q q q q q q q q q
q What is shared between all of these organisms?
q q q q q q q
A. They are made of cells, whose nuclei enclose their DNA.
q q q q q q q q q
B. They obtain their energy from sunlight.
q q q q q
C. They produce and use adenosine triphosphate (ATP).
q q q q q q
D. Their genome contains at least 1000 genes.
q q q q q q
E. All of the above.
q q q
2 All cells …
q q
A. have membrane transport proteins.
q q q
B. synthesize proteins on the ribosome. q q q q
C. replicate their genome by DNA polymerization. q q q q q
D. transcribe their genetic information by RNA polymerization.
q q q q q q
E. All of the above. q q q
3 Imagine a segment of DNA (within a gene) encoding a certain amount of information in
q q q q q q q q q q q q q q
its nucleotide sequence. When this segment is fully transcribed into mRNA and then translated
q q q q q q q q q q q q q q
into protein, in general, …
q q q q q
A. the protein sequence would carry more information compared to the DNA and mRNA
q q q q q q q q q q q q
sequences, because its alphabet has 20 letters.
q q q q q q q
q B. the protein sequence would carry less information compared to the DNA and mRNA
q q q q q q q q q q q q q
sequences, because several codons can correspond to one amino acid.
q q q q q q q q q q
C. the amount of information in the mRNA sequence is lower, because the mRNA has
q q q q q q q q q q q q q
been transcribed using only one of the DNA strands as the template.
q q q q q q q q q q q q
D. the amount of information in the mRNA sequence is higher, because several mRNA
q q q q q q q q q q q q
molecules can be transcribed from one DNA molecule.
q q q q q q q q
4 Which of the following processes that happens inside a cell DOES NOT normally require
q q q q q q q q q q q q q
consumption of free energy by the cell?
q q q q q q q
, A. Replication of the genetic material q q q q
B. Import of nutrients from the environment
q q q q q
C. Diffusion of small molecules within the cell q q q q q q
D. Regulation of gene expression q q q
E. Synthesis of enzymes that catalyze cellular reactions q q q q q q
5 Which of the following would you N OT expect to find in a bacterial cell?
q q q q q q q q q q q q q q
A. Swimming using flagella q q
B. Having a cell wall around the plasma membrane q q q q q q q
q C. ATP production in mitochondria
q q q q
D. Protein production on the ribosome q q q q
E. Sexual exchange of DNA with other bacteriaq q q q q q
6 To trace family relationships between distantly related organisms such as humans, algae,
q q q q q q q q q q q
bacteria, and archaea, one should compare their genomes in regions …
q q q q q q q q q q q
A. that evolve rapidly.
q q
B. that have a higher mutation rate.
q q q q q
C. that code for proteins.
q q q
D. where mutations are hardly tolerated.
q q q q
E. where most mutations are selectively neutral.
q q q q q
7 Laboratory strains of the model organism Escherichia coli that are resistant to antibiotics
q q q q q q q q q q q q
are very often used in research laboratories as well as in the biotechnology industry. If cultures
q q q q q q q q q q q q q q q q
q of such bacteria were allowed to contaminate the environment uncontrollably, it is possible that
q q q q q q q q q q q q q
qat some point, pathogenic bacteria such as Neisseria meningitidis (which causes meningitis and
q q q q q q q q q q q q
can cause death, especially in children) could acquire the same antibiotic-resistance gene,
q q q q q q q q q q q q
q causing a meningitis outbreak that is difficult to treat. In this scenario, which of the following
q q q q q q q q q q q q q q q
mechanisms is a more likely source of the antibiotic-resistance gene in N. meningitidis?
q q q q q q q q q q q q q
A. Random new gene generation q q q
B. Intragenic mutation q
C. Gene duplication q
D. DNA segment shuffling q q
E. Horizontal gene transfer q q
8 A virus …
q q
A. is a type of cell.
q q q q
, B. has genetic material made of proteins.
q q q q q
C. can only infect a single host species.
q q q q q q
D. can act as a vector for gene transfer.
q q q q q q q
E. cannot persist in its host for more than one cell generation.
q q q q q q q q q q
9 Which of the following does NOT typically involve horizontal gene transfer?
q q q q q q q q q q
A. Sexual reproduction in humans q q q
B. Bacteriophage infection of bacteria q q q
C. The evolutionary history of the eukaryotic cell
q q q q q q
D. The accidental duplication of a small region of a bacterial chromosome followed by
q q q q q q q q q q q q
cell division
q q
E. Introduction of plasmids into bacteria in a laboratory q q q q q q q
10 Gene duplication can give rise to homologous genes that are part of gene families. For
q q q q q q q q q q q q q q
example, there are six actin genes in the genome of most mammalian species. In humans, the
q q q q q q q q q q q q q q q q
ACTB gene, which encodes a cytoskeletal actin, is expressed ubiquitously, while ACTC1 is
q q q q q q q q q q q q q
expressed mainly in cardiac cells. Although bacteria lack the eukaryotic cytoskeletal
q q q q q q q q q q q
qorganization, the bacterial MreB gene bears recognizable sequence similarity to mammalian
q q q q q q q q q q
actin genes and codes for a protein that is similar to actin in structure and function. Which of the
q q q q q q q q q q q q q q q q q q q
following statements is true about these genes?
q q q q q q q
A. ACTB is homologous to ACTC1 but not to MreB.
q q q q q q q q
B. ACTB is orthologous to ACTC1 but not to MreB.
q q q q q q q q
C. ACTB is paralogous to ACTC1 but not to MreB.
q q q q q q q q
D. MreB is orthologous to ACTB but not to ACTC1.
q q q q q q q q
E. ACTB is paralogous to both ACTC1 and MreB.
q q q q q q q
11 Out of nearly 5000 protein-coding gene families, there is a set of nearly 300 conserved
q q q q q q q q q q q q q q
gene families that are found in species from all domains of life. When one looks at the general
q q q q q q q q q q q q q q q q q q
q functions assigned to these gene families, it is found that …
q q q q q q q q q q
A. the majority of them function in cell-to-cell signaling.
q q q q q q q
B. the majority of them are poorly characterized.
q q q q q q
C. more than one-third of them are involved in translation or amino acid transport
q q q q q q q q q q q q
and m etabolism.
q q q
D. more than one-half of the shared families are involved in DNA replication
q q q q q q q q q q q
and transcription.
q q
E. Nearly all of them are involved in energy production and carbohydrate metabolism.
q q q q q q q q q q q
, 12 Which of the following is true regarding Escherichia coli?
q q q q q q q q
A. Most of our understanding about mitosis comes from studies on this model organism.
q q q q q q q q q q q q
B. It is a rod-shaped bacterium that can only grow in the gut of humans and
q q q q q q q q q q q q q q
other vertebrates.
q q
C. Two strains of E. coli can differ by up to 0.1% in their genomes.
q q q q q q q q q q q q q
D . E. coli strain K-12 encodes about 4300 proteins.
q q q q q q q q q q
E. The E. coli (strain K-12) genome is about 430 million nucleotide pairs long.
q q q q q q q q q q q q q
13 Which of the following is NOT true regarding the tree of life?
q q q q q q q q q q q
A. Most bacteria and archaea have 1000 to 6000 genes in their genomes.
q q q q q q q q q q q
B. Eukaryotes are more similar to archaea than to bacteria with respect to the
q q q q q q q q q q q q
proteins that act on their DNA.
q q q q q q
C. Most bacteria and archaea have genome sizes between one and ten million nucleotide
q q q q q q q q q q q q
pairs, whereas eukaryotic genomes can be millions of times larger.
q q q q q q q q q q
D. Archaeal species were thought to belong to the eukaryotic world before
q q q q q q q q q q
sequence analysis placed them in a separate domain of life.
q q q q q q q q q q
E. Photosynthetic bacteria are thought to be the ancestors of the eukaryotic chloroplasts. q q q q q q q q q q q
14 A mutation in the cdc28 gene in the budding yeast Saccharomyces cerevisiae causes cell-
q q q q q q q q q q q q q
cycle arrest, giving rise to unbudded cells that look like “dumbbells.” Treatment of wild-type
q q q q q q q q q q q q q q
cells with nocodazole, a drug that destabilizes some cytoskeletal polymers, leads to a similar
q q q q q q q q q q q q q q
phenotype. Based only on these observations, which statement is true regarding cdc28?
q q q q q q q q q q q q
A. cdc28 codes for a master regulatory kinase that phosphorylates other proteins.
q q q q q q q q q q
B. Nocodazole binds to the protein coded by the cdc28 gene.q q q q q q q q q
C. The product of the cdc28 gene is responsible for resistance to nocodazole.
q q q q q q q q q q q
D. The product of the cdc28 gene is involved in cell cycle regulation.
q q q q q q q q q q q
E. The product of cdc28 destabilizes the same cytoskeletal polymers that
q q q q q q q q q
qnocodazole also destabilizes. q q
15 Which of the following structures is exclusively found in eukaryotic cells?
q q q q q q q q q q
A. Plasma membrane q
B. Cell wall q
C. Chromosome
D. Ribosome
E. Lysosome
