Deck 15: Beyond the Cell: Cell Adhesions, cell Junctions, and Extracellular Structures

Question 1

The primary function of each of the following is for adhesion of a cell to another cell or the extracellular matrix except

A)desmosomes.
B)hemidesmosomes.
C)plaques.
D)connexins.
E)cadherins.

Answer 1

D

Question 2

Which of the following regulates paracellular transport?

A)adherens junctions
B)gap junctions
C)desmosomes
D)tight junctions
E)hemidesmosomes

Answer 2

D

Question 3

Mice lacking plakoglobin have skin defects but usually die from

A)cancer.
B)muscular dystrophy.
C)heart failure.
D)Ehlers-Danlos syndrome.
E)scurvy.

Answer 3

C

Question 4

Which of the following pairs shares a similar function?

A)adhesive junction-tight junction
B)desmotubule-gap junction
C)tight junction-gap junction
D)plaque-plasmodesma
E)connexon-desmosome

Question 5

Each of the following is a component of focal adhesions except

A)integrin.
B)talin.
C)α-actinin.
D)vinculin.
E)plakoglobin.

Question 6

Which of the following junctions is most abundant in tissues such as skin that are required to resist significant mechanical stress?

A)gap junctions
B)desmosomes
C)focal adhesions
D)tight junctions
E)All are abundant in tissues resisting stress.

Question 7

An autoimmune disorder in which an immune response targets Type V collagen fibers is most likely to affect the

A)skin.
B)heart.
C)lungs.
D)stomach.
E)tongue.

Question 8

Which of the following functions like a fence to block membrane protein movement between the apical and basolateral regions of an intestinal epithelial cell plasma membrane?

A)gap junctions
B)desmosomes
C)adherens junction
D)hemidesmosomes
E)tight junction

Question 9

Each of the following cell junctions is found in intestinal epithelial cells except

A)gap junctions.
B)hemidesmosomes.
C)tight junctions.
D)desmosomes.
E)All are found in intestinal epithelial cells.

Question 10

In animals,the extracellular matrix plays important roles in each of the following processes except

A)cell division.
B)cell motility.
C)DNA replication.
D)cell differentiation.
E)cell adhesion.

Question 11

Each of the following components is associated with the primary cell wall except

A)cellulose microfibrils.
B)hemicelluloses.
C)pectins.
D)glycoproteins.
E)lignins.

Question 12

The finding that integrin-linked kinase (ILK)is required for focal adhesion function but its kinase activity is not,suggests the protein acts as a

A)direct connection to the ECM.
B)linker protein.
C)scaffolding protein.
D)cytoskeletal filament.
E)signaling protein.

Question 13

Which of the following stabilizes homophilic interactions between the extracellular domains of cadherins on neighboring cells?

A)hyaluronate
B)proteoglycans
C)Ca²⁺
D)integrins
E)talin

Question 14

While investigating a medical condition,you discover that the patient has an autoimmune disease that targets and destroys fibroblasts.This disorder would most likely affect

A)fibrin activity in blood clotting.
B)annulus formation.
C)hyaluronate lubrication of joints.
D)collagen production.
E)primary cell wall deposition.

Question 15

Ehlers-Danlos syndrome and scurvy both are characterized by defects in

A)fibronectin.
B)desmosomes.
C)collagen.
D)dystrophin.
E)elastin.

Question 16

N-CAM mediates interactions between neural cells and is a member of which of the following protein families?

A)catenins
B)cadherins
C)selectins
D)immunoglobulin superfamily (IgSF)proteins
E)lectins

Question 17

Which of the following is the correct order for the synthesis of the plant cell wall?

A)middle lamella; primary cell wall; secondary cell wall
B)primary cell wall; middle lamella; secondary cell wall
C)secondary cell wall; primary cell wall; middle lamella
D)middle lamella; secondary cell wall; primary cell wall
E)primary cell wall; secondary cell wall; middle lamella

Question 18

Selectins mediate interactions between which of the following?

A)leukocytes and blood vessel endothelial cells
B)muscle cells and ECM
C)nerve cells and other nerve cells
D)intestinal epithelial cells with neighboring cells
E)skin cells in different skin layers

Question 19

Polarized cells are characterized by

A)random orientation within a tissue.
B)being surrounded on all sides by a basement membrane.
C)junctions only to ECM and not to other cells.
D)distinct apical and basolateral ends of the cell.
E)formation of several connected layers of cells.

Question 20

You discover a dog suffering from an autoimmune response.On further investigation,you find that the cells of various tissues are loosely arranged and do not have characteristic shapes,and the animal is prone to hemorrhaging because of poor blood clotting.Based on these results,the target of the autoimmune response is most likely to be

A)fibronectins.
B)laminins.
C)extensins.
D)pectins.
E)elastins.

Question 21

In cartilage,proteoglycans form large complexes by attaching to

A)glycosaminoglycans.
B)collagen.
C)hyaluronate.
D)laminin.
E)elastin.

Question 22

Each of the following is a component of the plant cell wall network except

A)hyaluronate.
B)cellulose.
C)extensin.
D)hemicellulose.
E)pectin.

Question 23

Which of the following forms the insoluble layer of aromatic alcohols found primarily in woody tissues?

A)hyaluronates
B)cadherins
C)proteoglycans
D)lignins
E)pectins

Question 24

Which of the following could you use experimentally to help you determine which carbohydrates are present on a cell's surface?

A)cadherins
B)proteoglycans
C)pectins
D)connexins
E)lectins

Question 25

A cluster of intracellular linker proteins associated with a junction is called a(n)

A)annulus.
B)connexon.
C)plaque.
D)tonofilament.
E)accessory protein complex.

Question 26

You suspect that an elderly patient's skin blistering is caused by an autoimmune disorder.If you are correct,the patient's serum likely contains antibodies directed against

A)talin.
B)vinculin.
C)α-actinin.
D)BPAG2.
E)actin.

Question 27

The primary function of focal contacts is

A)cell-ECM adhesion.
B)cell-cell adhesion.
C)cell-cell communication.
D)paracellular pathway regulation.
E)establishing cell polarity.

Question 28

Elastin molecules are crosslinked to each other by

A)hydrogen bonds between hydroxylysines and hydroxyprolines.
B)covalent bonds between lysines.
C)covalent bonds between prolines.
D)hydrophobic interactions between hydroxyprolines and glycines.
E)peptide bonds between glycines.

Question 29

Collagens interact directly with which of the following types of junctions?

A)gap junctions
B)tight junctions
C)hemidesmosomes
D)desmosomes
E)None of the above are correct.

Question 30

Each of the following is a good functional match between animal and plant extracellular structures or fibers except

A)elastins-extensins.
B)extracellular matrix-cell wall.
C)collagens-cellulose.
D)proteoglycans-hemicelluloses.
E)fibronectins-pectins.

Question 31

Which of the following is associated with the lubrication of joints?

A)chondroitin sulfate
B)lignins
C)hyaluronate
D)keratan sulfate
E)pectins

Question 32

To investigate the role of cadherin in early development,you continuously treat frog zygotes with antibodies that bind EP-cadherin.You most likely would find that

A)cell division stops but the existing cells organize to form a small,properly organized blastula.
B)the cells associate only loosely and fail to form a properly organized blastula.
C)the cells associate only loosely but skip the blastula stage to develop into a normal frog.
D)the cells divide uncontrollably and form a large tumor-like mass.
E)blastula formation and subsequent development proceed normally.

Question 33

The type of adhesive junction that connects epithelial cells to the basal lamina is a

A)hemidesmosome.
B)desmosome.
C)gap junction.
D)tight junction.
E)focal contact.

Question 34

Which of the following is responsible for the impermeability of the epithelium lining the bladder and ducts connecting the pancreas to the digestive tract?

A)adherens junctions
B)gap junctions
C)desmosomes
D)tight junctions
E)hemidesmosomes

Question 35

Animal extracellular matrices contain each of the following except

A)collagens.
B)proteoglycans.
C)pectins.
D)fibronectins.
E)elastins.

Question 36

Each of the following is true about basal lamina except

A)it serves as a structural support.
B)it allows for movement of some small molecules but blocks movement of large molecules.
C)it can influence cell migrations in certain areas of the body.
D)it contains collagen type IV,proteoglycans,laminins,and entactin.
E)it is composed primarily of fibronectin.

Question 37

Which of the following aspects of collagen would be directly affected by a defect in procollagen peptidase?

A)synthesis
B)secretion
C)extracellular assembly
D)binding to fibronectin
E)all of the above

Question 38

Costameres,in which cytosolic actin filaments are linked to extracellular laminins through dystrophin-dystrogylcan complexes,are found in

A)skin cells.
B)intestinal epithelial cells.
C)striated muscle cells.
D)nerve cells.
E)pancreatic cells.

Question 39

Which of the following is a primary structural constituent of the plant cell secondary wall?

A)hemicellulose
B)extensin
C)collagen
D)pectin
E)cellulose

Question 40

Fibronectin interacts with each of the following except

A)fibrin.
B)collagen.
C)heparin.
D)integrin.
E)pectin.

Question 41

A(n)________ is the ring of cytoplasm through a plasmodesmata.

Question 42

________ are the animal cell surface proteins that link the cytoskeleton to the extracellular matrix.

Question 43

Expansins are proteins that loosen up cell walls so cells can elongate.Auxin is thought to activate expansins by

A)aligning cellulose microfibrils.
B)activating protons pumps to decrease pH in a section of the cell wall.
C)depositing lignin molecules between cellulose fibrils.
D)increasing turgor pressure.
E)increasing pectin hydration.

Question 44

Each of the following proteins is a component of both costameres and focal adhesions except

A)β1-integrin.
B)vinculin.
C)talin.
D)α-actinin.
E)dystrophin.

Question 45

________ are Ca²⁺-dependent adhesive glycoproteins that function in animal cell-cell recognition and adhesion.

Question 46

Animal cells attach to adhesive glycoproteins such as ________ and ________ in the extracellular matrix.

Question 47

Although MCF-10A breast cancer cells grow well on Matrigel-coated culture dishes,the cells will form cysts of polarized cells that produce milk only when

A)extra collagen is added to the Matrigel.
B)extra fibronectin is added to the Matrgel.
C)extra elastin is added to the Matrigel.
D)the Matrigel layer is thick enough to form a 3D environment.
E)the Matrigel layer is present as a very thin layer on the culture dishes.

Question 48

A major component of collagen is the amino acid ________,which is the only one small enough to fit in the interior of the collagen triple helix structure.

Question 49

________ are insoluble polymers of aromatic alcohols that primarily are found in woody tissues.

Question 50

A cadherin forms a ________ extracellular interaction with a ________ on another cell.

Question 51

________ are cytosolic channels through openings in plant cell walls.

Question 52

The three most common glycosaminoglycans (GAGs)are ________,________,and ________.

Question 53

Each of the following is true about plant pectins except

A)pectins are long unbranched polymers.
B)pectins form the matrix in which cellulose microfibrils are embedded.
C)pectins bind adjacent cell walls together.
D)pectins trap and bind water molecules.
E)pectins have a gel-like consistency.

Question 54

Free ________ molecules provide lubrication to joints between movable bones.

Question 55

Numerous collagen fibrils associate to form a collagen ________.

Question 56

The ________ serves as structural support in tissue organization and as a permeability barrier.

Question 57

Each of the following is true about plant rosettes except

A)rosettes are localized in the plasma membrane.
B)rosettes are cellulose-synthesizing enzyme complexes.
C)rosette deposition of cellulose microfibrils is directed by microtubules.
D)rosettes move in the plasma membrane to deposit growing cellulose microfibrils.
E)rosettes deposit cellulose microfibrils only in the middle lamella.

Question 58

________ are polysaccharides composed of repeating disaccharide units that are the carbohydrate part of some proteoglycans.

Question 59

One of the most important roles of proteoglycans is to trap ________ to form a ________ matrix.

Question 60

The ________ is the layer of cell wall material shared between adjacent plant cells.