LS 7C Practice Exam
Questions AND VERIFIED
CORRECT ANSWERS
GRADED A+ [LATEST
UPDATE] 100% GUARANTEED
PASS
In many cells, the adhesion to the extracellular matrix through integrins causes the activation of
kinases in the cytoplasm. This suggests that: - CORRECT ANSWER-integrins promote the
activation of signal-transduction pathways.
Vascular endothelial growth factor (abbreviated VEGF and pronounced "Veg-F") is a peptide
signaling molecule related to platelet-derived growth factor. VEGF is important in the formation
of the circulatory system because its signaling pathway causes the formation of blood vessels in
developing embryos during normal development. Tumors also produce and secrete VEGF,
causing the formation of new blood vessels that supply these tumors. Given what you know
about the different kinds of cell signaling and VEGF, which one of the following statements is
TRUE? - CORRECT ANSWER-VEGF is a paracrine signaling molecule because it binds to receptors
on cells at the site where new blood vessels are needed.
In complex multicellular organisms, bulk flow is an important physiologic character. Why is bulk
flow a necessary condition of complex multicellularity? - CORRECT ANSWER-Organisms
exhibiting complex multicellularity are large and have cells/tissues that are not in contact with
, their environment. Systems that can overcome the limits of diffusion must occur for basic
physiologic processes to occur.
A decrease in cell adhesion, by the introduction of an experimental substance to a tissue,
compromises the structural integrity of the tissue. Which cell junction would MOST likely be
affected by this treatment causing a decrease in the strength of the tissue? - CORRECT
ANSWER-adherens junctions
If a mutation occurred in the cadherin gene so that the cytoplasmic domain no longer attached
to the cytoskeleton, which of the following would occur? - CORRECT ANSWER-Cadherins in
desmosomes would no longer be anchored to intermediate filaments.
Figure 9.15 shows how normal signaling works with a Ras protein acting downstream of a
receptor kinase. You examine a cell line in which Ras is always activated even in the absence of a
signaling molecule. This causes constant activation of the kinases in the MAP kinase pathway.
Which of the following conditions would be MOST likely to turn off this abnormally active
signaling pathway? - CORRECT ANSWER-the addition of a drug that prevents the final kinase
from interacting with its target protein in the nucleus
A newly discovered signaling molecule that binds to a G protein-coupled receptor is being
studied by using cells maintained in cell culture. Preliminary results show that the binding of
this new ligand causes the activation of adenylyl cyclase. In the next part of this study, a non-
hydrolyzable version of GTP (a form of GTP that cannot be converted to GDP) is added to the
cell culture dishes and is taken up by the cells. Which of the following would you expect to
observe? - CORRECT ANSWER-increased cAMP, increased protein kinase A activity
When a doctor suspects that a patient may have diabetes, she will often have the patient take a
glucose challenge test. After the patient drinks a large amount of sugary solution, his blood is
drawn and the circulating levels of glucose in the blood are determined. Which of the following
curves do you expect from a patient with diabetes? - CORRECT ANSWER-curve B
Questions AND VERIFIED
CORRECT ANSWERS
GRADED A+ [LATEST
UPDATE] 100% GUARANTEED
PASS
In many cells, the adhesion to the extracellular matrix through integrins causes the activation of
kinases in the cytoplasm. This suggests that: - CORRECT ANSWER-integrins promote the
activation of signal-transduction pathways.
Vascular endothelial growth factor (abbreviated VEGF and pronounced "Veg-F") is a peptide
signaling molecule related to platelet-derived growth factor. VEGF is important in the formation
of the circulatory system because its signaling pathway causes the formation of blood vessels in
developing embryos during normal development. Tumors also produce and secrete VEGF,
causing the formation of new blood vessels that supply these tumors. Given what you know
about the different kinds of cell signaling and VEGF, which one of the following statements is
TRUE? - CORRECT ANSWER-VEGF is a paracrine signaling molecule because it binds to receptors
on cells at the site where new blood vessels are needed.
In complex multicellular organisms, bulk flow is an important physiologic character. Why is bulk
flow a necessary condition of complex multicellularity? - CORRECT ANSWER-Organisms
exhibiting complex multicellularity are large and have cells/tissues that are not in contact with
, their environment. Systems that can overcome the limits of diffusion must occur for basic
physiologic processes to occur.
A decrease in cell adhesion, by the introduction of an experimental substance to a tissue,
compromises the structural integrity of the tissue. Which cell junction would MOST likely be
affected by this treatment causing a decrease in the strength of the tissue? - CORRECT
ANSWER-adherens junctions
If a mutation occurred in the cadherin gene so that the cytoplasmic domain no longer attached
to the cytoskeleton, which of the following would occur? - CORRECT ANSWER-Cadherins in
desmosomes would no longer be anchored to intermediate filaments.
Figure 9.15 shows how normal signaling works with a Ras protein acting downstream of a
receptor kinase. You examine a cell line in which Ras is always activated even in the absence of a
signaling molecule. This causes constant activation of the kinases in the MAP kinase pathway.
Which of the following conditions would be MOST likely to turn off this abnormally active
signaling pathway? - CORRECT ANSWER-the addition of a drug that prevents the final kinase
from interacting with its target protein in the nucleus
A newly discovered signaling molecule that binds to a G protein-coupled receptor is being
studied by using cells maintained in cell culture. Preliminary results show that the binding of
this new ligand causes the activation of adenylyl cyclase. In the next part of this study, a non-
hydrolyzable version of GTP (a form of GTP that cannot be converted to GDP) is added to the
cell culture dishes and is taken up by the cells. Which of the following would you expect to
observe? - CORRECT ANSWER-increased cAMP, increased protein kinase A activity
When a doctor suspects that a patient may have diabetes, she will often have the patient take a
glucose challenge test. After the patient drinks a large amount of sugary solution, his blood is
drawn and the circulating levels of glucose in the blood are determined. Which of the following
curves do you expect from a patient with diabetes? - CORRECT ANSWER-curve B
