ALL 18 CHAPTERS COVERED
, Chapter 01: Analytic Questions, Introduction to the Study of Cell and Molecular Biology
1. Consider some questions about cell structure or function that you
would be interested in answering. Would the data required to answer
the question be easier to collect by working on an entire plant or
animal or on a population of cultured cells? What might be the
advantages and disadvantages of working on a whole organism
versus a cell culture?
Ans: The specific answer would depend on the question asked.
Advantages of working with a cell culture include the ability to
study a single cell type, ease of obtaining large numbers of
cells, ability to minimize number of unknown variables by
using carefully controlled in vitro conditions. The advantage of
using a whole organism is that information obtained is more
meaningful in understanding the role of the process in the
overall activity of the organism. For example, one might want
to study glucose transport across the plasma membrane of
cultured liver cells in response to insulin, but the results would
not tell you much about the role of this process in maintaining
proper blood glucose levels.
Difficulty: Difficult
Section Reference:
1.2
2. Figure 1.3 shows an intestinal epithelial cell with large numbers of
microvilli. What is the advantage to the organism of having these
microvilli? What do you expect would happen to an individual that
lacked such microvilli as the result of an inherited mutation?
Ans: They greatly increase the surface area/volume ratio of the cell,
allowing much greater exchange between the cell and the
lumen of the intestine. Would be unable to absorb sufficient
nutrients from the lumen to survive.
Difficulty: Medium
Section Reference:
1.2
Page 1
, Chapter 01: Analytic Questions, Introduction to the Study of Cell and Molecular Biology
3. The first human cells to be successfully cultured were derived from a
malignant tumor. Do you think this simply reflects the availability of
cancer cells, or might such cells be better subjects for cell culture?
Why?
Ans: Cancer cells grow in a much less controlled manner than
normal cells, which is why they continue to proliferate in the
body. Cancer cells tend to have fewer requirements for growth
and are therefore more readily cultured in diverse media than
normal cells. Culturing such cells was a logical first step in the
development of culture conditions.
Difficulty: Difficult
Section Reference:
1.2
4. The drawings of plant and animal cells in Figure 1.8b,c include certain
structures that are present in plant cells but absent in animal cells.
How do you think each of these structures affects the life of the
plant?
Ans: A major difference between plant and animal cells is the
presence of chloroplasts and their associated light harvesting
molecules which allow plants to convert light energy to
ATP. Plant cells also typically have large vacuoles that consist
of fused membrane bound organelles. In plants, vacuoles are
often filled with water and help maintain hydrostatic pressure
or turgor.
Difficulty: Difficult
Section Reference:
1.3
Page 2
, Chapter 01: Analytic Questions, Introduction to the Study of Cell and Molecular Biology
5. It was noted that cells possess receptors on their surface that allow
them to respond to specific stimuli. Many cells in the human body
possess receptors that allow them to bind specific hormones that
circulate in the blood. Why do you think these hormone receptors are
important? What would be the effect on the physiological activities of
the body if cells lacked these receptors, or if all cells had the same
receptors?
Ans: These receptors mark specific cells as targets for particular
hormones. Without such receptors, cells would not be able to
bind a specific hormone and thus would not be able to respond
to it. If all cells had the same receptors, hormones would not
be able to selectively activate specific target cells. All cells
would become potential targets.
Difficulty: Easy
Section Reference:
1.2
6. If you were to argue that viruses are living organisms, what features
of viral structure and function might you use in your argument?
Ans: That viruses contain genetic material; that they are capable of
producing more of themselves, albeit only inside a host cell;
that they contain complex biological macromolecules; that they
evolve. These are all important criteria of living organisms.
Difficulty: Difficult
Section Reference:
1.8
7. If we presume that activities within cells do occur in a manner
analogous to that shown in the Rube Goldberg cartoon of Figure 1.7,
how would this differ from a human activity, such as building a car on
an assembly line or shooting a free throw in a basketball game?
Ans: Activities in cells are not directed by agents with a conscious,
purposeful goal. Activities that occur in a cell must be directed
and regulated by mechanisms operating within the system.
Difficulty: Difficult
Section Reference:
1.2
Page 3
, Chapter 01: Analytic Questions, Introduction to the Study of Cell and Molecular Biology
1. Consider some questions about cell structure or function that you
would be interested in answering. Would the data required to answer
the question be easier to collect by working on an entire plant or
animal or on a population of cultured cells? What might be the
advantages and disadvantages of working on a whole organism
versus a cell culture?
Ans: The specific answer would depend on the question asked.
Advantages of working with a cell culture include the ability to
study a single cell type, ease of obtaining large numbers of
cells, ability to minimize number of unknown variables by
using carefully controlled in vitro conditions. The advantage of
using a whole organism is that information obtained is more
meaningful in understanding the role of the process in the
overall activity of the organism. For example, one might want
to study glucose transport across the plasma membrane of
cultured liver cells in response to insulin, but the results would
not tell you much about the role of this process in maintaining
proper blood glucose levels.
Difficulty: Difficult
Section Reference:
1.2
2. Figure 1.3 shows an intestinal epithelial cell with large numbers of
microvilli. What is the advantage to the organism of having these
microvilli? What do you expect would happen to an individual that
lacked such microvilli as the result of an inherited mutation?
Ans: They greatly increase the surface area/volume ratio of the cell,
allowing much greater exchange between the cell and the
lumen of the intestine. Would be unable to absorb sufficient
nutrients from the lumen to survive.
Difficulty: Medium
Section Reference:
1.2
Page 1
, Chapter 01: Analytic Questions, Introduction to the Study of Cell and Molecular Biology
3. The first human cells to be successfully cultured were derived from a
malignant tumor. Do you think this simply reflects the availability of
cancer cells, or might such cells be better subjects for cell culture?
Why?
Ans: Cancer cells grow in a much less controlled manner than
normal cells, which is why they continue to proliferate in the
body. Cancer cells tend to have fewer requirements for growth
and are therefore more readily cultured in diverse media than
normal cells. Culturing such cells was a logical first step in the
development of culture conditions.
Difficulty: Difficult
Section Reference:
1.2
4. The drawings of plant and animal cells in Figure 1.8b,c include certain
structures that are present in plant cells but absent in animal cells.
How do you think each of these structures affects the life of the
plant?
Ans: A major difference between plant and animal cells is the
presence of chloroplasts and their associated light harvesting
molecules which allow plants to convert light energy to
ATP. Plant cells also typically have large vacuoles that consist
of fused membrane bound organelles. In plants, vacuoles are
often filled with water and help maintain hydrostatic pressure
or turgor.
Difficulty: Difficult
Section Reference:
1.3
Page 2
, Chapter 01: Analytic Questions, Introduction to the Study of Cell and Molecular Biology
5. It was noted that cells possess receptors on their surface that allow
them to respond to specific stimuli. Many cells in the human body
possess receptors that allow them to bind specific hormones that
circulate in the blood. Why do you think these hormone receptors are
important? What would be the effect on the physiological activities of
the body if cells lacked these receptors, or if all cells had the same
receptors?
Ans: These receptors mark specific cells as targets for particular
hormones. Without such receptors, cells would not be able to
bind a specific hormone and thus would not be able to respond
to it. If all cells had the same receptors, hormones would not
be able to selectively activate specific target cells. All cells
would become potential targets.
Difficulty: Easy
Section Reference:
1.2
6. If you were to argue that viruses are living organisms, what features
of viral structure and function might you use in your argument?
Ans: That viruses contain genetic material; that they are capable of
producing more of themselves, albeit only inside a host cell;
that they contain complex biological macromolecules; that they
evolve. These are all important criteria of living organisms.
Difficulty: Difficult
Section Reference:
1.8
7. If we presume that activities within cells do occur in a manner
analogous to that shown in the Rube Goldberg cartoon of Figure 1.7,
how would this differ from a human activity, such as building a car on
an assembly line or shooting a free throw in a basketball game?
Ans: Activities in cells are not directed by agents with a conscious,
purposeful goal. Activities that occur in a cell must be directed
and regulated by mechanisms operating within the system.
Difficulty: Difficult
Section Reference:
1.2
Page 3
