Essential Cell Biology (Ch. 1-4)
Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated
that there are between 10 million and 100 million different species. Despite this wide variety of
organisms, it remains difficult to define what it means to say something is alive. Which of the
following can be described as the smallest living organism?
A) DNA
B) cell
C) organelle
D) protein - ANS-B
Indicate whether the following statements are true or false. If the statement is false, explain why
it is false.
A. The paramecium is a multicellular microorganism covered with hairlike cilia.
B. Cells of different types can have different chemical requirements.
C. The branchlike extensions that sprout from a single nerve cell in a mammalian brain can
extend over several hundred micrometers. - ANS-A) False. The paramecium is a single-celled
organism.
B) True.
C) True.
For each of the following sentences, fill in the blanks with the best word or phrase selected from
the list below. Not all words or phrases will be used; each word or phrase should be used only
once.
Cells can be very diverse: superficially, they come in various sizes, ranging from bacterial cells
such as Lactobacillus, which is a few ___ in length, to larger cells such as a frog's egg, which
has a diameter of about one ___. Despite the diversity, cells resemble each other to an
astonishing degree in their chemistry. For example, the same 20 ___ are used to make proteins.
Similarly, the genetic information of all cells is stored in their ___. Although ___ contain the
same types of molecules as cells, their inability to reproduce themselves by their own efforts
means that means that they are not considered the living matter.
amino acids, micrometer(s), viruses, DNA, millimeter(s), yeast, fatty acids, plants, meter, -
ANS-Micrometers
Millimeters
Amino acids
DNA
viruses
How does cellular specialization serve multicellular organisms and how might a high degree of
specialization be detrimental? - ANS-In a multicellular organism, the specialization of cells
,creates a division of labor and each type of cell relies on the activities of other cell types for
survival. This cooperation between specialized cells is essential for the organism as a whole. If
one of these overly specialized cells were removed from the context of the organism, it would
not have the capabilities needed to generate offspring and would probably not even live very
long.
The flow of genetic information is controlled by a series of biochemical reactions that result in
the production of proteins, each with its own specific order of amino acids. Choose the correct
series of biochemical reactions from the options presented here.
A) replication, transcription, translation
B) replication, translation, transcription
C) translation, transcription, replication
D) translation, replication, transcription - ANS-A
Proteins are important architectural and catalytic components within the cell, helping to
determine its chemistry, its shape, and its ability to respond to changes in the environment.
Remarkably, all of the different proteins in a cell are made from the same 20 __________. By
linking them in different sequences, the cell can make protein molecules with different
conformations and surface chemistries, and therefore different
functions.
(a) nucleotides.
(b) sugars.
(c) amino acids.
(d) fatty acids. - ANS-C
Which statement is NOT true about mutations?
(a) A mutation is a change in the DNA that can generate offspring less fit for survival than their
parents.
(b) A mutation can be a result of imperfect DNA duplication.
(c) A mutation is a result of sexual reproduction.
(d) A mutation is a change in the DNA that can generate offspring that are as fit for survival as
their parents are. - ANS-C
Changes in DNA sequence from one generation to the next may result in offspring that
are altered in fitness compared with their parents. The process of change and selection
over the course of many generations is the basis of __________.
(a) mutation.
(b) evolution.
(c) heredity.
(d) reproduction. - ANS-B
Select the option that best finishes the following statement: "Evolution is a process
__________."
(a) that can be understood based on the principles of mutation and selection.
,(b) that results from repeated cycles of adaptation over billions of years.
(c) by which all present-day cells arose from 4-5 different ancestral cells.
(d) that requires hundreds of thousands of years. - ANS-A
Select the option that correctly finishes the following statement: "A cell's genome
_________________."
(a) is defined as all the genes being used to make protein.
(b) contains all of a cell's DNA.
(c) constantly changes, depending upon the cell's environment.
(d) is altered during embryonic development. - ANS-B
Which statement is NOT true about the events/conclusions from studies during the mid-1800s
surrounding the discovery of cells?
(a) Cells came to be known as the smallest universal building block of living organisms.
(b) Scientists came to the conclusion that new cells can form spontaneously from the remnants
of ruptured cells.
(c) Light microscopy was essential in demonstrating the commonalities between plant and
animal tissues.
(d) New cells arise from the growth and division of previously existing cells. - ANS-B
What unit of length would you generally use to measure an atypical plant or animal cell?
(a) centimeters
(b) nanometers
(c) millimeters
(d) micrometers ` - ANS-D
Match the type of microscopy on the left with the corresponding description provided
below. There is one best match for each.
A. confocal
B. transmission electron
C. fluorescence
D. phase-contrast
E. scanning electron
F. bright-field
___ uses a light microscope with an optical component to take advantage of the different
refractive indices of light passing through different regions of the cell.
___ employs a light microscope and requires that samples be fixed and stained in order
to reveal cellular details.
___ requires the use of two sets of filters. The first filter narrows the wavelength range
that reaches the specimen and the second blocks out all wavelengths that pass
back up to the eyepiece except for those emitted by the dye in the sample.
___ scans the specimen with a focused laser beam to obtain a series of two-dimensional
optical sections, which can be used to reconstruct an image of the s - ANS-D
, F
C
A
B
E
Indicate whether the following statements are true or false. If the statement is false, explain why
it is false.
A) The nucleus of an animal cell is round, small, and difficult to distinguish using light
microscopy.
B) The presence of the plasma membrane can be inferred by the well-defined boundary of the
cell.
C) The cytosol is fairly empty, containing a limited number of organelles, which allows room for
rapid movement via diffusion. - ANS-A. False. The nucleus is one of the largest organelles and
is the easiest organelle to discern within a typical cell.
B. True.
C. False. The cytosol is actually brimming with individual proteins, protein fibers, extended
membrane systems, transport vesicles, and small molecules. And although cellular components
do move by diffusion, the rate of movement is limited by the space available and the size of the
component in question.
Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both
standard fluorescence microscopy and confocal microscopy to observe specific details in the
cell. Even though fluorescence permits better visualization, the resolving power is essentially
the same as that of a standard light microscope because the resolving power of a microscope is
limited by the __________ of light.
(a) absorption
(b) intensity
(c) filtering
(d) wavelength - ANS-D
What is the smallest distance two points can be separated and still resolved using light
microscopy?
(a) 20 nm
(b) 0.2 µm
(c) 2 µm
(d) 200 µm - ANS-B
By definition, prokaryotic cells do not possess __________.
(a) a nucleus.
(b) replication machinery.
(c) ribosomes.
(d) membrane bilayers. - ANS-A
Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated
that there are between 10 million and 100 million different species. Despite this wide variety of
organisms, it remains difficult to define what it means to say something is alive. Which of the
following can be described as the smallest living organism?
A) DNA
B) cell
C) organelle
D) protein - ANS-B
Indicate whether the following statements are true or false. If the statement is false, explain why
it is false.
A. The paramecium is a multicellular microorganism covered with hairlike cilia.
B. Cells of different types can have different chemical requirements.
C. The branchlike extensions that sprout from a single nerve cell in a mammalian brain can
extend over several hundred micrometers. - ANS-A) False. The paramecium is a single-celled
organism.
B) True.
C) True.
For each of the following sentences, fill in the blanks with the best word or phrase selected from
the list below. Not all words or phrases will be used; each word or phrase should be used only
once.
Cells can be very diverse: superficially, they come in various sizes, ranging from bacterial cells
such as Lactobacillus, which is a few ___ in length, to larger cells such as a frog's egg, which
has a diameter of about one ___. Despite the diversity, cells resemble each other to an
astonishing degree in their chemistry. For example, the same 20 ___ are used to make proteins.
Similarly, the genetic information of all cells is stored in their ___. Although ___ contain the
same types of molecules as cells, their inability to reproduce themselves by their own efforts
means that means that they are not considered the living matter.
amino acids, micrometer(s), viruses, DNA, millimeter(s), yeast, fatty acids, plants, meter, -
ANS-Micrometers
Millimeters
Amino acids
DNA
viruses
How does cellular specialization serve multicellular organisms and how might a high degree of
specialization be detrimental? - ANS-In a multicellular organism, the specialization of cells
,creates a division of labor and each type of cell relies on the activities of other cell types for
survival. This cooperation between specialized cells is essential for the organism as a whole. If
one of these overly specialized cells were removed from the context of the organism, it would
not have the capabilities needed to generate offspring and would probably not even live very
long.
The flow of genetic information is controlled by a series of biochemical reactions that result in
the production of proteins, each with its own specific order of amino acids. Choose the correct
series of biochemical reactions from the options presented here.
A) replication, transcription, translation
B) replication, translation, transcription
C) translation, transcription, replication
D) translation, replication, transcription - ANS-A
Proteins are important architectural and catalytic components within the cell, helping to
determine its chemistry, its shape, and its ability to respond to changes in the environment.
Remarkably, all of the different proteins in a cell are made from the same 20 __________. By
linking them in different sequences, the cell can make protein molecules with different
conformations and surface chemistries, and therefore different
functions.
(a) nucleotides.
(b) sugars.
(c) amino acids.
(d) fatty acids. - ANS-C
Which statement is NOT true about mutations?
(a) A mutation is a change in the DNA that can generate offspring less fit for survival than their
parents.
(b) A mutation can be a result of imperfect DNA duplication.
(c) A mutation is a result of sexual reproduction.
(d) A mutation is a change in the DNA that can generate offspring that are as fit for survival as
their parents are. - ANS-C
Changes in DNA sequence from one generation to the next may result in offspring that
are altered in fitness compared with their parents. The process of change and selection
over the course of many generations is the basis of __________.
(a) mutation.
(b) evolution.
(c) heredity.
(d) reproduction. - ANS-B
Select the option that best finishes the following statement: "Evolution is a process
__________."
(a) that can be understood based on the principles of mutation and selection.
,(b) that results from repeated cycles of adaptation over billions of years.
(c) by which all present-day cells arose from 4-5 different ancestral cells.
(d) that requires hundreds of thousands of years. - ANS-A
Select the option that correctly finishes the following statement: "A cell's genome
_________________."
(a) is defined as all the genes being used to make protein.
(b) contains all of a cell's DNA.
(c) constantly changes, depending upon the cell's environment.
(d) is altered during embryonic development. - ANS-B
Which statement is NOT true about the events/conclusions from studies during the mid-1800s
surrounding the discovery of cells?
(a) Cells came to be known as the smallest universal building block of living organisms.
(b) Scientists came to the conclusion that new cells can form spontaneously from the remnants
of ruptured cells.
(c) Light microscopy was essential in demonstrating the commonalities between plant and
animal tissues.
(d) New cells arise from the growth and division of previously existing cells. - ANS-B
What unit of length would you generally use to measure an atypical plant or animal cell?
(a) centimeters
(b) nanometers
(c) millimeters
(d) micrometers ` - ANS-D
Match the type of microscopy on the left with the corresponding description provided
below. There is one best match for each.
A. confocal
B. transmission electron
C. fluorescence
D. phase-contrast
E. scanning electron
F. bright-field
___ uses a light microscope with an optical component to take advantage of the different
refractive indices of light passing through different regions of the cell.
___ employs a light microscope and requires that samples be fixed and stained in order
to reveal cellular details.
___ requires the use of two sets of filters. The first filter narrows the wavelength range
that reaches the specimen and the second blocks out all wavelengths that pass
back up to the eyepiece except for those emitted by the dye in the sample.
___ scans the specimen with a focused laser beam to obtain a series of two-dimensional
optical sections, which can be used to reconstruct an image of the s - ANS-D
, F
C
A
B
E
Indicate whether the following statements are true or false. If the statement is false, explain why
it is false.
A) The nucleus of an animal cell is round, small, and difficult to distinguish using light
microscopy.
B) The presence of the plasma membrane can be inferred by the well-defined boundary of the
cell.
C) The cytosol is fairly empty, containing a limited number of organelles, which allows room for
rapid movement via diffusion. - ANS-A. False. The nucleus is one of the largest organelles and
is the easiest organelle to discern within a typical cell.
B. True.
C. False. The cytosol is actually brimming with individual proteins, protein fibers, extended
membrane systems, transport vesicles, and small molecules. And although cellular components
do move by diffusion, the rate of movement is limited by the space available and the size of the
component in question.
Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both
standard fluorescence microscopy and confocal microscopy to observe specific details in the
cell. Even though fluorescence permits better visualization, the resolving power is essentially
the same as that of a standard light microscope because the resolving power of a microscope is
limited by the __________ of light.
(a) absorption
(b) intensity
(c) filtering
(d) wavelength - ANS-D
What is the smallest distance two points can be separated and still resolved using light
microscopy?
(a) 20 nm
(b) 0.2 µm
(c) 2 µm
(d) 200 µm - ANS-B
By definition, prokaryotic cells do not possess __________.
(a) a nucleus.
(b) replication machinery.
(c) ribosomes.
(d) membrane bilayers. - ANS-A
