Cellular Biology
Chapter 1: Cellular Biology
MULTIPLE CHOICE
1. Which statement best describes the cellular function of metabolic absorption?
a. Cells can produce proteins. c. Cells can take in and use nutrients.
b. Cells can secrete digestive enzymes. d. Cells can synthesize fats.
ANS: C
In metabolic absorption, all cells take in and use nutrients and other substances from their
surroundings. The remaining options are not inclusive in their descriptions of cellular
metabolic absorption.
PTS: 1 REF: Page 2
2. Most of a cell’s genetic information, including RNA and DNA, is contained in the:
a. Mitochondria c. Nucleolus
b. Ribosome d. Lysosome
ANS: C
The nucleus contains the nucleolus, a small dense structure composed largely of RNA, most
of the cellular DNA, and the DNA-binding proteins, such as the histones, which regulate its
activity. The other options do not contain most of a cell’s genetic information.
PTS: 1 REF: Page 2
3. Which component of the cell produces hydrogen peroxide (H2O2) by using oxygen to remove
hydrogen atoms from specific substrates in an oxidative reaction?
a. Lysosomes c. Ribosomes
b. Peroxisomes d. Oxyhydrosomes
ANS: B
Peroxisomes are so named because they usually contain enzymes that use oxygen to remove
hydrogen atoms from specific substrates in an oxidative reaction that produces H 2 O2 , which is
a powerful oxidant and potentially destructive if it accumulates or escapes from peroxisomes.
Ribosomes are RNA-protein complexes (nucleoproteins) that are synthesized in the nucleolus
and secreted into the cytoplasm through pores in the nuclear envelope called nuclear pore
complexes. Lysosomes are saclike structures that originate from the Golgi complex and
contain more than 40 digestive enzymes called hydrolases, which catalyze bonds in proteins,
lipids, nucleic acids, and carbohydrates. Oxyhydrosomes are involved in enzyme production.
PTS: 1 REF: Page 8
4. Which cell component is capable of cellular autodigestion when it is released during cell
injury?
a. Ribosome c. Smooth endoplasmic reticulum
b. Golgi complex d. Lysosomes
ANS: D
,Cellular Biology
The lysosomal membrane acts as a protective shield between the powerful digestive enzymes
within the lysosome and the cytoplasm, preventing their leakage into the cytoplasmic matrix.
Disruption of the membrane by various treatments or cellular injury leads to a release of the
lysosomal enzymes, which can then react with their specific substrates, causing cellular
self-digestion. The other options do not correctly describe this process.
PTS: 1 REF: Pages 7-8
5. What is the sequence of steps in the development of a digestive enzyme by the pancreas cells
from the initial transcription to the release from the cell?
a. The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the
ribosome for synthesis, and is transported in a secretory vesicle to the cell
membrane.
b. The enzyme is transcribed from RNA by DNA in the nucleus, proceeds to the
lysosome for synthesis, and is transported in an encapsulated membrane to the cell
membrane.
c. The enzyme is transcribed by the mitochondria in the nucleus, proceeds to the
ribosome for synthesis, and is transported in a cytoskeleton to the cell membrane.
d. The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the
Golgi complex for synthesis, and is transported in a cytosol to the cell membrane.
ANS: A
The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the ribosome for
synthesis, and is transported in a secretory vesicle to the cell membrane. The other options do
not correctly describe this process.
PTS: 1 REF: Page 7 | Figure 1-5
6. During which phase of the cell cycle is DNA synthesized?
a. G1 c. G2
b. S d. M
ANS: B
The four designated phases of the cell cycle are: (1) the G1 phase (G = gap), which is the
period between the M phase (M = mitosis) and the start of DNA synthesis; (2) the S phase (S
= synthesis), during which DNA is synthesized in the cell nucleus; (3) the G2 phase, during
which RNA and protein synthesis occurs, the period between the completion of DNA
synthesis and the next phase (M); and (4) the M phase, which includes nuclear and
cytoplasmic division.
PTS: 1 REF: Page 37
7. What organic compound facilitates transportation across cell membranes by acting as
receptors, transport channels for electrolytes, and enzymes to drive active pumps?
a. Lipids c. Proteins
b. Proteases d. Carbohydrates
ANS: C
,Cellular Biology
Proteins act as (1) recognition and binding units (receptors) for substances moving in and out
of the cell; (2) pores or transport channels for various electrically charged particles called ions
or electrolytes and specific carriers for amino acids and monosaccharides; and (3) specific
enzymes that drive active pumps that promote the concentration of certain ions, particularly
potassium (K+), within the cell while keeping concentrations of other ions, for example,
sodium (Na+), below the concentrations found in the extracellular environment. The other
options do not correctly describe this process.
PTS: 1 REF: Page 13 | Page 15
8. Understanding the various steps of proteolytic cascades, such as caspase-mediated apoptosis
and complement cascades, may be useful in designing drug therapy for which human
diseases?
a. Cardiac and vascular disorders
b. Autoimmune and malignant disorders
c. Gastrointestinal and renal disorders
d. Endocrine and gastrointestinal disorders
ANS: B
Understanding the various steps involved in this process is crucial for designing drug
interventions. Dysregulation of proteases features prominently in many human diseases,
including cancer, autoimmunity, and neurodegenerative disorders. The other options do not
correctly describe this process.
PTS: 1 REF: Page 15
9. Which structure prevents water-soluble molecules from entering cells across the plasma
membrane?
a. Carbohydrate chains c. Membrane channel proteins
b. Glycoprotein channels d. Lipid bilayer
ANS: D
The bilayer’s structure accounts for one of the essential functions of the plasma membrane. It
is impermeable to most water-soluble molecules (molecules that dissolve in water) because
the water-soluble molecules are insoluble in the oily core region. The bilayer serves as a
barrier to the diffusion of water and hydrophilic substances while allowing lipid-soluble
molecules, such as oxygen (O2) and carbon dioxide (CO2), to diffuse through it readily. The
other options do not correctly describe this process.
PTS: 1 REF: Pages 12-13
10. The fluid mosaic model explains:
a. How a cell membrane functions
b. Why our bodies appear to be solid
c. How tissue is differentiated
d. How fluid moves between the intracellular and extracellular compartments
ANS: A
The fluid mosaic model accounts for the flexibility of cellular membranes, their self-sealing
properties, and their impermeability to many substances. The remaining options do not
explain the mosaic model.
, Cellular Biology
PTS: 1 REF: Page 12 | What's New box
11. Which form of cell communication is used to communicate within the cell itself and with
other cells in direct physical contact?
a. Protein channel (gap junction)
b. Plasma membrane–bound signaling molecules (involving receptors)
c. Hormone secretion such as neurotransmitters
d. Extracellular chemical messengers such as ligands
ANS: A
Cells communicate by using hundreds of kinds of signal molecules, for example, insulin.
Cells communicate in three main ways; they display plasma membrane–bound signaling
molecules (receptors) that affect the cell itself and other cells in direct physical contact. The
other options do not correctly describe this process.
PTS: 1 REF: Page 20
12. Which mode of chemical signaling uses blood to transport communication to cells some
distance away?
a. Paracrine c. Neurotransmitter
b. Autocrine d. Hormonal
ANS: D
Chemical signaling can be classified into three categories: (1) local-chemical mediator, (2)
hormone, and (3) neurotransmitter. In the local-chemical mediator model, the secreted
chemical acts on the cells in the immediate environment. Hormones are used for
communication with distant target cells. For example, cells can secrete a chemical and rely on
the blood system to deliver the signal to a distant cell. Finally, neurotransmitters are secreted
by neurons to stimulate an adjoining cell. For example, a neuron might secrete acetylcholine
to stimulate the movement of a muscle cell.
PTS: 1 REF: Page 20
13. Which mode of chemical signaling uses local chemical mediators that are quickly taken up,
destroyed, or immobilized?
a. Paracrine c. Neurotransmitter
b. Autocrine d. Hormone
ANS: A
In paracrine signaling, cells secrete local chemical mediators that are quickly taken up,
destroyed, or immobilized. The other options do not correctly describe this process.
PTS: 1 REF: Page 20
14. Neurotransmitters affect the postsynaptic membrane by binding to:
a. Lipids c. Amphipathic lipids
b. Ribosomes d. Receptors
ANS: D
In each type of chemical signaling, the target cell receives the signal by first attaching to its
receptors. The other options do not correctly describe this process.
Chapter 1: Cellular Biology
MULTIPLE CHOICE
1. Which statement best describes the cellular function of metabolic absorption?
a. Cells can produce proteins. c. Cells can take in and use nutrients.
b. Cells can secrete digestive enzymes. d. Cells can synthesize fats.
ANS: C
In metabolic absorption, all cells take in and use nutrients and other substances from their
surroundings. The remaining options are not inclusive in their descriptions of cellular
metabolic absorption.
PTS: 1 REF: Page 2
2. Most of a cell’s genetic information, including RNA and DNA, is contained in the:
a. Mitochondria c. Nucleolus
b. Ribosome d. Lysosome
ANS: C
The nucleus contains the nucleolus, a small dense structure composed largely of RNA, most
of the cellular DNA, and the DNA-binding proteins, such as the histones, which regulate its
activity. The other options do not contain most of a cell’s genetic information.
PTS: 1 REF: Page 2
3. Which component of the cell produces hydrogen peroxide (H2O2) by using oxygen to remove
hydrogen atoms from specific substrates in an oxidative reaction?
a. Lysosomes c. Ribosomes
b. Peroxisomes d. Oxyhydrosomes
ANS: B
Peroxisomes are so named because they usually contain enzymes that use oxygen to remove
hydrogen atoms from specific substrates in an oxidative reaction that produces H 2 O2 , which is
a powerful oxidant and potentially destructive if it accumulates or escapes from peroxisomes.
Ribosomes are RNA-protein complexes (nucleoproteins) that are synthesized in the nucleolus
and secreted into the cytoplasm through pores in the nuclear envelope called nuclear pore
complexes. Lysosomes are saclike structures that originate from the Golgi complex and
contain more than 40 digestive enzymes called hydrolases, which catalyze bonds in proteins,
lipids, nucleic acids, and carbohydrates. Oxyhydrosomes are involved in enzyme production.
PTS: 1 REF: Page 8
4. Which cell component is capable of cellular autodigestion when it is released during cell
injury?
a. Ribosome c. Smooth endoplasmic reticulum
b. Golgi complex d. Lysosomes
ANS: D
,Cellular Biology
The lysosomal membrane acts as a protective shield between the powerful digestive enzymes
within the lysosome and the cytoplasm, preventing their leakage into the cytoplasmic matrix.
Disruption of the membrane by various treatments or cellular injury leads to a release of the
lysosomal enzymes, which can then react with their specific substrates, causing cellular
self-digestion. The other options do not correctly describe this process.
PTS: 1 REF: Pages 7-8
5. What is the sequence of steps in the development of a digestive enzyme by the pancreas cells
from the initial transcription to the release from the cell?
a. The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the
ribosome for synthesis, and is transported in a secretory vesicle to the cell
membrane.
b. The enzyme is transcribed from RNA by DNA in the nucleus, proceeds to the
lysosome for synthesis, and is transported in an encapsulated membrane to the cell
membrane.
c. The enzyme is transcribed by the mitochondria in the nucleus, proceeds to the
ribosome for synthesis, and is transported in a cytoskeleton to the cell membrane.
d. The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the
Golgi complex for synthesis, and is transported in a cytosol to the cell membrane.
ANS: A
The enzyme is transcribed from DNA by RNA in the nucleus, proceeds to the ribosome for
synthesis, and is transported in a secretory vesicle to the cell membrane. The other options do
not correctly describe this process.
PTS: 1 REF: Page 7 | Figure 1-5
6. During which phase of the cell cycle is DNA synthesized?
a. G1 c. G2
b. S d. M
ANS: B
The four designated phases of the cell cycle are: (1) the G1 phase (G = gap), which is the
period between the M phase (M = mitosis) and the start of DNA synthesis; (2) the S phase (S
= synthesis), during which DNA is synthesized in the cell nucleus; (3) the G2 phase, during
which RNA and protein synthesis occurs, the period between the completion of DNA
synthesis and the next phase (M); and (4) the M phase, which includes nuclear and
cytoplasmic division.
PTS: 1 REF: Page 37
7. What organic compound facilitates transportation across cell membranes by acting as
receptors, transport channels for electrolytes, and enzymes to drive active pumps?
a. Lipids c. Proteins
b. Proteases d. Carbohydrates
ANS: C
,Cellular Biology
Proteins act as (1) recognition and binding units (receptors) for substances moving in and out
of the cell; (2) pores or transport channels for various electrically charged particles called ions
or electrolytes and specific carriers for amino acids and monosaccharides; and (3) specific
enzymes that drive active pumps that promote the concentration of certain ions, particularly
potassium (K+), within the cell while keeping concentrations of other ions, for example,
sodium (Na+), below the concentrations found in the extracellular environment. The other
options do not correctly describe this process.
PTS: 1 REF: Page 13 | Page 15
8. Understanding the various steps of proteolytic cascades, such as caspase-mediated apoptosis
and complement cascades, may be useful in designing drug therapy for which human
diseases?
a. Cardiac and vascular disorders
b. Autoimmune and malignant disorders
c. Gastrointestinal and renal disorders
d. Endocrine and gastrointestinal disorders
ANS: B
Understanding the various steps involved in this process is crucial for designing drug
interventions. Dysregulation of proteases features prominently in many human diseases,
including cancer, autoimmunity, and neurodegenerative disorders. The other options do not
correctly describe this process.
PTS: 1 REF: Page 15
9. Which structure prevents water-soluble molecules from entering cells across the plasma
membrane?
a. Carbohydrate chains c. Membrane channel proteins
b. Glycoprotein channels d. Lipid bilayer
ANS: D
The bilayer’s structure accounts for one of the essential functions of the plasma membrane. It
is impermeable to most water-soluble molecules (molecules that dissolve in water) because
the water-soluble molecules are insoluble in the oily core region. The bilayer serves as a
barrier to the diffusion of water and hydrophilic substances while allowing lipid-soluble
molecules, such as oxygen (O2) and carbon dioxide (CO2), to diffuse through it readily. The
other options do not correctly describe this process.
PTS: 1 REF: Pages 12-13
10. The fluid mosaic model explains:
a. How a cell membrane functions
b. Why our bodies appear to be solid
c. How tissue is differentiated
d. How fluid moves between the intracellular and extracellular compartments
ANS: A
The fluid mosaic model accounts for the flexibility of cellular membranes, their self-sealing
properties, and their impermeability to many substances. The remaining options do not
explain the mosaic model.
, Cellular Biology
PTS: 1 REF: Page 12 | What's New box
11. Which form of cell communication is used to communicate within the cell itself and with
other cells in direct physical contact?
a. Protein channel (gap junction)
b. Plasma membrane–bound signaling molecules (involving receptors)
c. Hormone secretion such as neurotransmitters
d. Extracellular chemical messengers such as ligands
ANS: A
Cells communicate by using hundreds of kinds of signal molecules, for example, insulin.
Cells communicate in three main ways; they display plasma membrane–bound signaling
molecules (receptors) that affect the cell itself and other cells in direct physical contact. The
other options do not correctly describe this process.
PTS: 1 REF: Page 20
12. Which mode of chemical signaling uses blood to transport communication to cells some
distance away?
a. Paracrine c. Neurotransmitter
b. Autocrine d. Hormonal
ANS: D
Chemical signaling can be classified into three categories: (1) local-chemical mediator, (2)
hormone, and (3) neurotransmitter. In the local-chemical mediator model, the secreted
chemical acts on the cells in the immediate environment. Hormones are used for
communication with distant target cells. For example, cells can secrete a chemical and rely on
the blood system to deliver the signal to a distant cell. Finally, neurotransmitters are secreted
by neurons to stimulate an adjoining cell. For example, a neuron might secrete acetylcholine
to stimulate the movement of a muscle cell.
PTS: 1 REF: Page 20
13. Which mode of chemical signaling uses local chemical mediators that are quickly taken up,
destroyed, or immobilized?
a. Paracrine c. Neurotransmitter
b. Autocrine d. Hormone
ANS: A
In paracrine signaling, cells secrete local chemical mediators that are quickly taken up,
destroyed, or immobilized. The other options do not correctly describe this process.
PTS: 1 REF: Page 20
14. Neurotransmitters affect the postsynaptic membrane by binding to:
a. Lipids c. Amphipathic lipids
b. Ribosomes d. Receptors
ANS: D
In each type of chemical signaling, the target cell receives the signal by first attaching to its
receptors. The other options do not correctly describe this process.
