Question 1

You are investigating cell localization by targeting the carbohydrates associated with various cell types.Based on this molecule's ability to bind various carbohydrates,which of the following would help determine which carbohydrates are found on the cell surface?

Accepted Answer

Lectins are proteins that bind specifically to carbohydrates. Therefore, targeting lectins would be a useful tool to determine which carbohydrates are found on the cell surface. The other options listed are proteins that play different roles in cell function and do not specifically bind carbohydrates.

Question 2

In the extracellular matrix of animal cells,collagen and elastin fibers are embedded with this matrix.

Accepted Answer

Collagen and elastin fibers in the extracellular matrix are embedded in a matrix composed of glycosaminoglycans and proteoglycans, which help provide structural support and hydration.

Question 3

A type of adhesive junction that is associated with the connection between an epithelial cell and the basal lamella is the

Accepted Answer

Hemidesmosomes connect epithelial cells to the basal lamina and are responsible for anchoring cells to the extracellular matrix. Desmosomes are adhesive junctions between cells, gap junctions allow for communication between cells, plasmodesmata are found in plant cells and allow for communication between cells, and focal contacts are involved in cell adhesion and cell signaling in non-epithelial cells.

Question 4

A collection of fibrous intracellular attachment proteins is called a(n)

Accepted Answer

A collection of fibrous intracellular attachment proteins is called a plaque. Tonofilaments are one of the components of a plaque. Connexons are transmembrane proteins that form gap junctions between cells. Annulus is the ring-shaped structure that holds the lens in place in the eye.

Question 5

The autoimmune response to desmosomes or desmosomal components (not hemidesmosomes)leads to a blistering skin disease known as

Accepted Answer

The autoimmune response to desmosomes or desmosomal components leads to the formation of autoantibodies that attack the desmosomes, causing the skin cells to separate and blister, leading to a condition known as pemphigus. Ehlers-Danlos syndrome is a genetic disorder that affects the connective tissues, syndecan is a type of transmembrane proteoglycan, junctional epidermolysis bullosa is a genetic disorder that affects the skin and mucous membranes, and listeriosis is a bacterial infection caused by Listeria monocytogenes.

Question 6

An elderly patient presents with blistering of the skin.You suspect an autoimmune disorder.If your suspicions are correct,the patient's serum should contain antibodies reactive to

Accepted Answer

BPAG (bullous pemphigoid antigen) is a component of the hemidesmosome in the skin, which is a structure that anchors the epidermis to the basement membrane. In autoimmune bullous pemphigoid, there are antibodies against BPAG, which lead to separation of the epidermis from the underlying dermis, resulting in blistering of the skin. Antibodies against talin and vinculin are found in autoimmune liver diseases, and antibodies against α-actinin are found in certain types of glomerulonephritis. Actin is a cytoskeletal protein and is not typically associated with autoimmune skin diseases.

Question 7

The insoluble layer of aromatic alcohols that are primarily found in woody tissues are the

Accepted Answer

Lignins are the insoluble layer of aromatic alcohols that are primarily found in woody tissues. Lignin acts as a glue to hold the cell walls together, giving support and rigidity to the plant's structure.

Question 8

Focal contact is associated with which of the following type of cellular junction?

Accepted Answer

Focal contact, also known as a focal adhesion, is a protein complex that connects the extracellular matrix to the actin cytoskeleton. Adhesive junctions are the type of cellular junctions that connect adjacent cells by anchoring them to the extracellular matrix, and they specifically include focal adhesions as a subtype. Gap junctions connect adjacent cells by forming channels that allow for direct communication, plasmodesmata are similar structures in plant cells, and tight junctions form a seal between adjacent cells to prevent substances from leaking through the intercellular space. None of these junctions are associated with focal contacts.

Question 9

The organ where you would most likely expect to find actin microfilaments continuous with adherens junctions is the

Accepted Answer

The organ where you would most likely find actin microfilaments continuous with adherens junctions is the heart, particularly in cardiac muscle tissue. Adherens junctions are critical for maintaining the integrity and strength of the heart during contraction, and actin microfilaments play a key role in this process. The other organs listed - liver, stomach, kidney, and brain - may have adherens junctions and actin microfilaments, but not in the same continuous manner as seen in the heart.

Question 10

The primary polysaccharides associated with the plant cell wall are the

Accepted Answer

Hemicelluloses and pectins are the primary polysaccharides associated with the plant cell wall. Therefore, choice E is the correct answer. Extensins and fibronectins are not primary polysaccharides associated with the plant cell wall.

Question 11

Collagens are associated with which of the following types of cellular junctions?

Accepted Answer

The answer of Collagens are associated with which of the...

Question 12

In performing research,you treat frog zygotes with antibodies that bind E-cadherin.As a result,you expect

Accepted Answer

E-cadherin is a protein involved in cell-cell adhesion. By treating frog zygotes with antibodies that bind E-cadherin, the cells would not be able to adhere to one another, and as a result, they would be loosely associated and abort development. This is the expected outcome for this experiment.

Question 13

Which of the following is mismatched with regard to similar excellular structures in plant and animal cells?

Accepted Answer

The answer of Which of the following is mismatched with...

Question 14

Of the proteoglycans associated with the extracellular matrix in vertebrates,which of the following is associated with the lubrication of joints?

Accepted Answer

Hyaluronate is the proteoglycan associated with the lubrication of joints as it forms a gel-like substance that helps reduce friction between joints. Chondroitin sulfate and keratan sulfate are primarily found in cartilage and play a role in its structural integrity. Glucuronate is a sugar molecule component of proteoglycans but does not have a specific association with joint lubrication. Mucoproteins are a type of glycoprotein and not specifically associated with joint lubrication.

Question 15

Some observations have suggested to researchers that substances associated with the extracellular matrix may be involved in cell migration.This has been observed with the cell marker CD44 on the surface of cancer cells and their ability to be separate from one another and to easily metastasize to other regions of the body.This is most likely due to the interaction of CD44 and

Accepted Answer

CD44 is known to interact with hyaluronate, a component of the extracellular matrix. This interaction allows for cancer cells to migrate and spread to other regions of the body.

Question 16

Which of the following is not associated with the basal lamina?

Accepted Answer

The basal lamina contains fibronectins, but they are not the most abundant supply found in this layer. The other choices are all associated with the basal lamina.

Question 17

The plant cell wall network is comprised of all of the following except

Accepted Answer

Hyaluronate is a glycosaminoglycan found primarily in animal connective tissue and is not a component of the plant cell wall network. The other options, cellulose, extensin, hemicellulose, and pectin, are all components of the plant cell wall network.

Question 18

The molecule of the extracellular matrix of animal cells that is associated with joint lubrication and friction reduction is

Accepted Answer

Hyaluronate, also known as hyaluronic acid, is a glycosaminoglycan that is a major component of synovial fluid, which lubricates and reduces friction in joints.

Question 19

The protein invasin is associated with

Accepted Answer

Invasin is a protein associated with Yersinia pseudotuberculosis, a bacterium that causes infections in animals and humans. Invasin allows the bacterium to invade and penetrate host cells.

Question 20

The type of cellular junction prominent in the stomach and kidney is the

Accepted Answer

The type of cellular junction prominent in the stomach and kidney is the tight junction, also known as the occluding junction. Tight junctions form a barrier between adjacent cells that selectively regulates the diffusion of ions and molecules, allowing for the tissues to maintain proper composition and prevent the leakage of contents. They are especially important in organs like the stomach and kidney, which undergo significant transport and exchange functions while protecting the body against harmful substances.

Quiz 17: Beyond the Cell: Cell Adhesions, cell Junctions, and Extracellular Structures