Chapter 15 Beyond The Cell: Cell Adhesions, Cell Junctions, and Extracellular Structures

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

Ca2+.

Polarized cells characterized by

Distinct apical and basolateral ends of the cell.

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

All are found in intestinal epithelial cells. (Gap junctions, hemidesmosmes, tight junctions and desmosomes).

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

DNA replication. (Cell division, cell motility, cell differentiation and cell adhesion are all correct).

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

Skin.

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

Desmosomes.

Selectins mediate interactions between which of the following?

Leukocytes and blood vessel endothelial cells.

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

Lignins. (Cellulose microfibrils, hemicelluloses, pectins, and glycoproteins are all correct).

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

Middle lamella; primary cell wall; secondary cell wall.

You discover a dog suffering from autoimmune response. On further investigation, you find that the cell 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

Fibronectins.

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

Scaffolding protein.

Each of the following is a component of focal adhesions except

Plakoglobin. (Integrin, talin, a-actinin, and vinculin are all correct).

Which of the following regulates paracellular transport?

Tight junctions.

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

Collagen production.

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

Hyaluronate.

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

Extracellular assembly.

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

Lectins.

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

Elastins-extensis. (Extracellular matrix-cell wall, collagens-cellulose, proteoglycans-hemicelluloses, and fibronectins-pectins are all correct).

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

The cells associate only loosely and fail to form a properly organized bastula.

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

None of the above are correct.

The primary function of focal contacts is

Cell-ECM adhesion.

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

Tight junctions.

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

Hemidesmosome.

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

Ligins.

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

Hyaluronate. (Cellulose, extensin, hemicellulose, and pectin are all correct).

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

Cellulose.

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

Plague.

Fibronectin interacts with each of the following except

Pectin. (Fibrin, collagen, heparin and integrin are all correct).

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

The Matrigel layer is thick enough to form a 3D environment.

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

Dystrophin. (B1-integrin, vinculin, talin, and a-actinin are all correct).

Each of the following is true about plant pectins except

Pectins are long unbranched polymers. (Pectins from the matrix in which cellulose microfibrils are embedded, pectins bind adjacent cell walls together, pectins trap and bind water molecules and pectins have a gel-like consistency are all correct).

The primary functions of each of the following is for adhesion of a cell or the extracellular matrix except

Connexins.

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

Immunoglobulin superfamily (IgSF) proteins.

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?

Tight junction.

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

Collagen.

Which of the following pairs shares a similar function?

Desmotubule-gap junction.

Elastin molecules are cross linked to each other by

Covalent bonds between lysines.

Each of the following is true about basal lamina except

It is composed primarily of fibronectin.

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 aganist

BPAG2.

Animal extracellular matrices contain each of the following except

Pectins.

In cartilage, proteoglycans from large complexes by attaching to

Hyaluronate.

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

Striated muscle cell.

Each of the following is true about plant rosettes except

Rosettes deposit cellulose microfibrils only in the middle lamella.

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

Activating protons pumps to decrease pH in a section of the cell wall.