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