,ESSENTIAL CELL BIOLOGY, FIFTH EDITION
CHAPTER 1: CELLS: THE FUNDAMENTAL UNITS OF LIFE
Unity and Diversity of Cells
1-1 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 unit?
(a) DNA (b) cell
(c) organelle
(d) protein
1-2 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.
1-3 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 they are not
considered living matter.
amino acids micrometer(s) viruses
DNA millimeter(s) yeast
fatty acids plants
meter plasma membranes
,1-4 How does cellular specialization serve multicellular organisms and how might a
high degree of specialization be detrimental?
1-5 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
1-6 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.
1-7 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.
1-8 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.
1-9 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.
, 1-10 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.
Cells Under the Microscope
1-11 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.
1-12 What unit of length would you generally use to measure a typical plant or animal
cell?
(a) centimeters
(b) nanometers
(c) millimeters
(d) micrometers
1-13 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
CHAPTER 1: CELLS: THE FUNDAMENTAL UNITS OF LIFE
Unity and Diversity of Cells
1-1 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 unit?
(a) DNA (b) cell
(c) organelle
(d) protein
1-2 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.
1-3 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 they are not
considered living matter.
amino acids micrometer(s) viruses
DNA millimeter(s) yeast
fatty acids plants
meter plasma membranes
,1-4 How does cellular specialization serve multicellular organisms and how might a
high degree of specialization be detrimental?
1-5 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
1-6 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.
1-7 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.
1-8 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.
1-9 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.
, 1-10 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.
Cells Under the Microscope
1-11 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.
1-12 What unit of length would you generally use to measure a typical plant or animal
cell?
(a) centimeters
(b) nanometers
(c) millimeters
(d) micrometers
1-13 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
