Question 1

You place mammary gland epithelial cells in culture and then treat them with enzymes that digest the surrounding extracellular matrix.What happens?

Accepted Answer

A)  The secretory and synthetic activities of the cells decrease.
B)  The secretory and synthetic activities of the cells increase.
C)  The cells die.
D)  The cells enunciate.
E)  The secretory and synthetic activities of the cells do not change. A

Question 2

The binding of lymphocytes to the endothelial lining of venules in peripheral lymph node frozen tissue sections could be blocked in what way? This demonstrated the existence of what kind of molecule?

Accepted Answer

A)  Treatment with antibodies against specific lymphocyte surface glycoproteins,selectins
B)  Treatment with antibodies against specific lymphocyte surface glycoproteins,IgSFs
C)  Treatment with antibodies against specific lymphocyte surface glycoproteins,integrins
D)  Treatment with antibodies against specific ECM glycoproteins,selectins
E)  Treatment with antibodies against specific ECM glycoproteins,cadherins A

Question 3

What explains the fact that plants lack the specialized junctions seen in animal cells?

Accepted Answer

A)  the presence of the large central vacuole
B)  the presence of chloroplasts
C)  the presence of the cell wall
D)  the presence of mitochondria
E)  the absence of centrioles,basal bodies,cilia and flagellae C

Question 4

Despite the presence of the blood-brain barrier,what cells,oddly enough,can pass through the blood-brain barrier by sending a signal that opens up the junction?

Accepted Answer

A)  red blood cells
B)  immune system cells
C)  platelets
D)  complement cells
E)  epithelial cells

Question 5

Pemphigus vulgaris __________.

Accepted Answer

A)  is characterized by a loss of epidermal cell-cell adhesion
B)  is an autoimmune disease
C)  is characterized by severe blistering of the skin
D)  is caused by the production of antibodies against one of the desmogleins
E)  All of these are correct.

Question 6

Basement membranes contain Type IV collagen,a nonfibrillar collagen organized in a flattened network.The Type IV collagen trimer has some interspersed nonhelical segments.What property does this confer upon basement membranes?

Accepted Answer

A)  strength
B)  flexibility
C)  extensibility
D)  transparency
E)  opacity

Question 7

The loss of cadherin function may be instrumental in what disease state?

Accepted Answer

A)  colds
B)  the spread of benign tumors
C)  the spread of malignant tumors
D)  influenza
E)  AIDS

Question 8

The cells of the epiblast of a developing mammalian embryo display what cell adhesion molecules on their surfaces,molecules that presumably promote their close association with one another?

Accepted Answer

A)  selectins
B)  E-cadherins
C)  P-cadherins
D)  integrins
E)  IgSFs

Question 9

To what is the cytoplasmic domain of integrins in the region of a focal contact connected via various adaptors?

Accepted Answer

A)  tubulins of the cytoskeleton
B)  actinin of the cytoskeleton
C)  actin of the cytoskeleton
D)  dynein of the cytoskeleton
E)  band III protein of the membrane

Question 10

You coat a Petri dish with fibronectin and proteoglycans and culture cells on the dish.The cells adhere to the dish.You repeat the experiment but this time add RGD tripeptides to the culture dish as the cells are added.What happens?

Accepted Answer

A)  The cells adhere as they normally do.
B)  The cells die immediately.
C)  The cells lyse immediately.
D)  The cells do not adhere to the dish.
E)  The cells immediately change their phenotype.

Question 11

What is thought to promote the release of future mesoderm cells from an epithelium and their transformation into mesenchymal cells?

Accepted Answer

A)  a stoppage in the expression of E-cadherin genes
B)  an increase in the expression of E-cadherin genes
C)  degradation of the cell membrane
D)  the cytoplasm taking on an anti-adhesive character
E)  autophagy of the nucleus

Question 12

You are given a tissue that has a large fibrillar component.The fibers are aligned parallel to each other and the long axis of the tissue.What can you conclude about the pulling forces experienced by this tissue?

Accepted Answer

The answer of You are given a tissue that has...

Question 13

Epidermolysis bullosa,an inherited blistering disease,is caused by ________.

Accepted Answer

A)  production of antibodies against hemidesmosome plaque proteins
B)  production of autoantibodies
C)  production of antibodies against spot desmosome plaque proteins
D)  genetic alterations in any one of a number of hemidesmosomal proteins
E)  production of antibodies against connexins

Question 14

Focal adhesions ________.

Accepted Answer

A)  have been implicated in cell locomotion
B)  contain integrins that develop transient interactions with the extracellular matrix
C)  collect information about the chemical properties of the extracellular environment
D)  transmit information to the cell interior that may lead to changes in cell adhesion,proliferation or survival
E)  All of these are correct.

Question 15

Desmosomes are particularly numerous in tissues _____________.

Accepted Answer

A)  that are subjected to mechanical stress
B)  like cardiac muscle
C)  like the epithelial layers of the skin
D)  like the epithelial layers of the uterine cervix
E)  All of these are correct.

Question 16

What would be the effect on primordial germ cells when an embryo is exposed to laminin-specific antibodies?

Accepted Answer

A)  They arrive at the developing gonad more quickly.
B)  Their movement to the developing gonad is disrupted.
C)  They begin to divide rapidly.
D)  They increase greatly in size.
E)  Their nuclei disintegrate.

Question 17

L1 is an IgSF molecule that has been shown to be important in neural development; it is thought that it may be involved in axon growth within the embryonic nervous system.What evidence supports this statement?

Accepted Answer

A)  L1 mutants always die.
B)  L1 mutants show deficits in their vision.
C)  People who die of L1-deficiency are often missing two large nerve tracts.
D)  People who die of L1-deficiency are often missing a significant portion of their brain.
E)  People who die of L1-deficiency are often missing a significant portion of their spinal cord.

Question 18

Why do cells flatten out as they make contact with a surface?

Accepted Answer

A)  They lose water.
B)  They extrude cytoplasm.
C)  They send out projections that make increasingly stable attachments.
D)  Their membranes stiffen.
E)  They make focal assignations.

Question 19

One small region of a human kidney tubule known as the thick ascending limb (or TAL)has tight junctions that are permeable to magnesium (Mg2+)ions.What is thought to account for the permeability of this tight junction to magnesium ions?

Accepted Answer

A)  The membrane in this region is leaky because of special phospholipids.
B)  Loops of claudin molecules that extend into the extracellular space form pores in the TAL.
C)  Loops of claudin molecules that extend into the cytoplasm form pores in the TAL.
D)  Loops of claudin molecules fully embedded in the TAL membrane form pores in the TAL.
E)  Claudin molecules form gap junctions that allow the passage of magnesium ions.

Question 20

In an integrin,what structure is it that crosses the lipid bilayer?

Accepted Answer

A)  a transmembrane pleated sheet
B)  a transmembrane spear
C)  a transmembrane plate
D)  a transmembrane helix
E)  a bent,curved leg

Exam 7: Interactions Between Cells and Their Environment

You place mammary gland epithelial cells in culture and then treat them with enzymes that digest the surrounding extracellular matrix.What happens?

The binding of lymphocytes to the endothelial lining of venules in peripheral lymph node frozen tissue sections could be blocked in what way? This demonstrated the existence of what kind of molecule?

What explains the fact that plants lack the specialized junctions seen in animal cells?

Despite the presence of the blood-brain barrier,what cells,oddly enough,can pass through the blood-brain barrier by sending a signal that opens up the junction?

Pemphigus vulgaris __________.

Basement membranes contain Type IV collagen,a nonfibrillar collagen organized in a flattened network.The Type IV collagen trimer has some interspersed nonhelical segments.What property does this confer upon basement membranes?

The loss of cadherin function may be instrumental in what disease state?

The cells of the epiblast of a developing mammalian embryo display what cell adhesion molecules on their surfaces,molecules that presumably promote their close association with one another?

To what is the cytoplasmic domain of integrins in the region of a focal contact connected via various adaptors?

You coat a Petri dish with fibronectin and proteoglycans and culture cells on the dish.The cells adhere to the dish.You repeat the experiment but this time add RGD tripeptides to the culture dish as the cells are added.What happens?

What is thought to promote the release of future mesoderm cells from an epithelium and their transformation into mesenchymal cells?

You are given a tissue that has a large fibrillar component.The fibers are aligned parallel to each other and the long axis of the tissue.What can you conclude about the pulling forces experienced by this tissue?

Epidermolysis bullosa,an inherited blistering disease,is caused by ________.

Focal adhesions ________.

Desmosomes are particularly numerous in tissues _____________.

What would be the effect on primordial germ cells when an embryo is exposed to laminin-specific antibodies?

L1 is an IgSF molecule that has been shown to be important in neural development; it is thought that it may be involved in axon growth within the embryonic nervous system.What evidence supports this statement?

Why do cells flatten out as they make contact with a surface?

One small region of a human kidney tubule known as the thick ascending limb (or TAL) has tight junctions that are permeable to magnesium (Mg²⁺) ions.What is thought to account for the permeability of this tight junction to magnesium ions?

In an integrin,what structure is it that crosses the lipid bilayer?

Exam 7: Interactions Between Cells and Their Environment

You place mammary gland epithelial cells in culture and then treat them with enzymes that digest the surrounding extracellular matrix.What happens?

The binding of lymphocytes to the endothelial lining of venules in peripheral lymph node frozen tissue sections could be blocked in what way? This demonstrated the existence of what kind of molecule?

What explains the fact that plants lack the specialized junctions seen in animal cells?

Despite the presence of the blood-brain barrier,what cells,oddly enough,can pass through the blood-brain barrier by sending a signal that opens up the junction?

Pemphigus vulgaris __________.

Basement membranes contain Type IV collagen,a nonfibrillar collagen organized in a flattened network.The Type IV collagen trimer has some interspersed nonhelical segments.What property does this confer upon basement membranes?

The loss of cadherin function may be instrumental in what disease state?

The cells of the epiblast of a developing mammalian embryo display what cell adhesion molecules on their surfaces,molecules that presumably promote their close association with one another?

To what is the cytoplasmic domain of integrins in the region of a focal contact connected via various adaptors?

You coat a Petri dish with fibronectin and proteoglycans and culture cells on the dish.The cells adhere to the dish.You repeat the experiment but this time add RGD tripeptides to the culture dish as the cells are added.What happens?

What is thought to promote the release of future mesoderm cells from an epithelium and their transformation into mesenchymal cells?

You are given a tissue that has a large fibrillar component.The fibers are aligned parallel to each other and the long axis of the tissue.What can you conclude about the pulling forces experienced by this tissue?

Epidermolysis bullosa,an inherited blistering disease,is caused by ________.

Focal adhesions ________.

Desmosomes are particularly numerous in tissues _____________.

What would be the effect on primordial germ cells when an embryo is exposed to laminin-specific antibodies?

L1 is an IgSF molecule that has been shown to be important in neural development; it is thought that it may be involved in axon growth within the embryonic nervous system.What evidence supports this statement?

Why do cells flatten out as they make contact with a surface?

One small region of a human kidney tubule known as the thick ascending limb (or TAL) has tight junctions that are permeable to magnesium (Mg2+) ions.What is thought to account for the permeability of this tight junction to magnesium ions?

In an integrin,what structure is it that crosses the lipid bilayer?

One small region of a human kidney tubule known as the thick ascending limb (or TAL) has tight junctions that are permeable to magnesium (Mg²⁺) ions.What is thought to account for the permeability of this tight junction to magnesium ions?