self test-7

1.Which of the following is not an example of a type of extracellular matrix?
A.basement membrane
B.the cornea of the eye
C.intermediate filaments
D.bone
2.Which of the following proteins of the ECM has a membrane bilayer-spanning
domain?
A.fibrillar collagen
B.heparan sulfate proteoglycans
C.fibronectin
minin
3.Embryos injected with antibodies to fibronectin show inhibited movement of
neural crest cells during development of the nervous system. These
experiments show that:
A.development of the neural crest involves the expression of antibody genes.
B.developing neurons must synthesize fibronectin.
C.fibronectin-antibody complexes form pathways for neural migration.
D.neurons in embryos must transiently bind to fibronectin during migration.
4.Although the protein families that comprise the ECM are very different, they
have one of the following characteristics in common:
A.They all have two or more distinct domains with specific binding sites.
B.They are all derived from proteins of the immune system.
C.They all have membrane-spanning domains.
D.None of them are attached to the cell.
5.Which of the following is not a role of integrins?
A.Integrins form a loose, hydrated gel in the ECM.
B.Integrins anchor cells to the substrate.
C.Integrins transmit signals to the intracellular compartment.
D.Integrins participate in specialized cell-to-cell adhesive structures
6.Integrin is to a focal adhesion as ? is to an adherens junction.
A.integrin
B.selectin
C.fibronectin
D.cadherin
7.The addition of a peptide with an RGD sequence would probably ? the
binding of cultured cells to a fibronectin-coated dish.
A.enhance
B.inhibit
C.have no effect on
D.none of the above
8.The addition of a peptide with an RGD sequence would probably ? the
binding of cultured cells to a collagen-coated or laminin-coated dish.
A.enhance
B.inhibit
C.have no effect on
D.none of the above
9.Focal adhesions are to cultured cells as ? are to cells in vivo.
A.plasmodesmata
B.gap junctions
C.cell walls
D.hemidesmosomes
10.Actin filaments are to focal adhesions as ? are to
hemidesmosomes.
A.myosin filaments
B.keratin filaments
C.microfilaments
D.cadherins
11.If a laboratory mouse had a mutation rendering the gene that codes for
the L-selectin protein nonfunctional, which of the following symptoms
would the animal exhibit?
A.blistering of the skin
B.clotting deficiencies
C.metastasis
D.inability to fight infection in the tissues
12.Calcium-dependent adhesion is to the cadherins as calcium-independent
adhesion is to the ? .
A.IgSF proteins
B.fibronectins
C.integrins
D.glycocalyx
13.To which category of proteins listed below are NCAM and VCAM most closely
related?
A.proteoglycans
B.antibodies
C.integrins
D.selectins
14.Which of the following cell types might have the highest number of
desmosomes?
A.smooth muscle cells
B.red blood cells
C.epithelial cells of the skin
D.nerve cells
15.How might anti-selectin antibodies act as anti-inflammatory drugs?
A.Anti-selectin antibodies prevent activated endothelial cells from expressing selectin.
B.Anti-selectin antibodies compete with carbohydrate ligands on neutrophil surfaces for selectin binding sites.
C.Anti-selectin antibodies prevent neutrophils from transiently binding vessel walls.
D.Anti-selectin antibodies prevent activated endothelial cells from producing platelet activating factor.
16.In going from the apical to the basal end of an epithelial cell, in what
order do the various cell surface junctions appear?
A.tight junction adherens junction desmosomes hemidesmosomes
B.desmosomes hemidesmosomes adherens junction tight junction
C.adherens junction tight junction desmosomes hemidesmosomes
D.tight junction adherens junction hemidesmosomes desmosomes
17.Cells of the heart must contract in synchrony to produce an effective heart
beat. The electrical signal telling each cell to contract must reach every cell of the heart at the same time. What kind of cell-to-cell junctions would you expect to find in heart tissue?
A.gap junctions
B.tight junctions
C.desmosome
D.adherens junctions
18.Plasmodesmata of plant cells have ? in common with gap junctions in
animal cells, but have ? that gap junctions lack.
A.connexin, connexon
B.cytoplasmic continuity, desmotubules
C.movement proteins, cytoplasmic continuity
D.desmotubules, cell walls
19.Fluorscein that is injected into one plant cell ? show up in adjacent
cells; DNA injected into one plant cell ? show up in adjacent cells.
A.would not; would not
B.would not; would
C.would; would not
D.would; would
20.That cancer cells often lack the gap junctions common to non-malignant cells
of the same type is evidence that
A.cancer is a disease of gap junctions.
B.GJIC is an element of controlled cell growth.
C.cancers all involve mutations in connexin genes.
D.connexin is responsible for cell adhesion.。