• Imagine a nerve cell that measures 125 µm x 1
µm x 1 µm. Predict how its surface area-tovolume ratio compare with those in the project
yesterday. Then calculate the ratio and check
out your prediction.
• How does the endosymbiotic theory explains
the evolution of eukaryotic cells?
• Antibiotics usually only effective against
bacteria and kill them by reacting with their cell
wall. Explain how it is possible that antibiotics
do not destroy other cells.
• Males afflicted with Kartagener’s syndrome are
sterile because of immotile sperm, and they
tend to suffer from lung infections. This
disorder has a genetic basis. Suggest what the
underlying defect might be.
• List organelles that you would expect to see in
large numbers in the following cells:
– Cells that specialize in water transport
– Cells that specialize in motion
– Cells that specialize in protein hormone production
– Cells that specialize in steroid hormone production
– Cells that specialize in detoxification
• Do plants have mitochondria? Why or why not?
• Describe structural and functional distinctions
between rough and smooth ER.
• Describe what the endomembrane system is and
how it is an interconnected entity within the cell.
• Describe how the location of ribosomes is related
to the type of protein that they make.
• Describe the path of a protein from the nucleus
where the genetic information is stored for its
production to its final destination outside of the
cell.
• How do bacteria perform cellular respiration if they
don’t have mitochondria and photosynthesis if they
don’t have chloroplasts?
• Explain how the structure of the Golgi apparatus
fits to perform its function.
• Explain how the structure of the smooth ER fits to
perform its function.
• Explain how the structure of microfilaments and
microtubules fit to perform their functions.
• Describe the location and the general structure of
the extracellular layer of cells. How does this
structure fit to perform its function?
• How would an animal cell be impacted by the loss
or depletion of an extracellular matrix?
• What would happen if plant cells did not have any
plasmodesmata?
And one more really evil question on
cell structure:
• The polypeptide chain that makes up a tight
junction waves back and forth through the
membrane four times, with two extracellular
loops, and one loop plus short C-terminal and
N-terminal tails in the cytoplasm. What would
you predict about the types of amino acid side
chains that make up the tight-junction
protein?
• Suggest a hypothesis to explain why the
thylakoid membranes of chloroplasts resemble
those of cyanobacteria.
• Contrast the cellular and DNA structures of
prokaryotes and eukaryotes.
• Although mutations are rare, they can still
provide considerable genetic variation in a
short period of time into bacterial populations.
Explain the reasons why.
• Distinguish among the three mechanisms that
are used to transfer DNA from one bacterial cell
to the next.
• In a rapidly changing environment, which
bacterial population would likely be more
successful, one that includes individuals capable
of conjugation or one that does not? Explain.
• If a nonpathogenic bacterium were to acquire
resistance to antibiotics, could this strain pose a
health risk to people? Explain.
• In general, how does DNA transfer among
bacteria affect the spread of resistance genes?
• Explain how viruses introduce genetic variation
in host bacteria.
• What are biofilms and how did they potentially
contribute to the evolution of cells?
• How has metagenomics contributed to our
understanding of prokaryotic diversity?
• Explain how Gram-positive and Gram-negative
bacteria differ and how this difference influence
potential treatment of bacterial diseases.
• Explain how quorum sensing can help bacteria
sense the presence of bacteria of other species
in their environment. How does it help with
bacteria of the same species?
• If bacteria only reproduce asexually, how can
they have such a wide genetic diversity?
• In a bag with a selectively permeable
membrane you have a solution of 4 % salt and 2
% starch. The bag is permeable to salt but not
to starch. You place this in a beaker with
distilled water. Draw this system, determine
the direction of the movement of various
substances and determine the type(s) of
transport used.
• Describe what happens with a plant cell when it
is placed in a hypotonic solution.
Has 4 M of
sucrose and 2 M
of glucose
Has 2 M of
sucrose and 4
M of glucose
• What is the tonicity of this system above?
• What is moving through the membrane in what
direction if the pores are about the size of glucose,
but glucose can still fit through them?
• Describe the direction of water movement and
final state of the cell if:
– Plant cell is placed in a hypotonic solution
– Animal cell is placed in a hypertonic solution
– Plan cell is placed in a hypertonic solution
– Animal cell is placed in an isotonic solution
• A researcher discovered a new drug that treats
lysosomal disorders. What kind of information
would you collect to know if the drug is able to
enter the cell membrane?
• The molar concentration of a sugar solution has
been determined to be 0.3 M. Calculate the
solute potential at 27 °C. Round your answer to
the nearest hundredth. What is the water
potential for this sample? If a cell is placed into
this solution that has a Ψc = -0.5 bar, what is the
tonicity of the cell compared to this solution?
Predict the direction of water movement.
• Calculate the water potential of a solution of
0.15 M sodium chloride in a beaker at 20 °C. If a
cell with a Ψ = -0.8 MPa is put into this solution,
what is the tonicity of the cell compared to the
solution? What is the direction of water
movement.
• At 20°C, a cell containing 0.6M glucose is in
equilibrium with its surrounding solution
containing 0.5M glucose in an open container.
What is the cell’s ΨP?
• In beaker B, what is the water potential of the
distilled water in the beaker, and of the beet core?
Which of the following statements is true for the diagrams above?
A. the beet core in beaker A is at equilibrium with the surrounding water
B. the beet core in beaker B will lose water to the surrounding
environment
C. The beet core in beaker B would be more turgid than the beet core in
beaker A
D. The beet core in beaker A is likely to gain so much water that its cells
will rupture
E. The cells in beet core B are likely to undergo plasmolysis.
Determine the type of transport
required in the following cases:
• Glucose moves into the cell from a higher
concentration area
• Oxygen gas moves into the cell
• Water moves into the cell
• Sucrose moves into the cell with the help of H+ ions.
• Sodium ions move out of the cell into a more
concentrated area
• Large oil droplet moves into the cell.
• Cholesterol molecules move into the cell by using
receptors.
• The cell releases a protein hormone.