Deck 10: Cell and Tissue Architecture: Cytoskeleton, Cell Junctions, and Extracellular Matrix

Question 1

Which of the following structures would be located in the dermis of the skin?

A)nerve endings
B)connective tissue
C)sweat glands
D)blood vessels
E)All of these choices are correct.

Answer 1

E

Question 2

Keratinocytes are pigment cells contained in the epidermis of skin.

Answer 2

False

Question 3

Which of the following statements about mammalian skin is INCORRECT?

A)The epidermis is an outer layer that provides a water-resistant, protective barrier.
B)The dermis is the layer below the epidermis containing connective tissue, blood vessels, and nerve endings that provides nutrients to the epidermis and a cushion layer for the body.
C)Epithelial cells in the epidermis are primarily composed of keratinocytes that protect underlying tissue.
D)A specialized form of extracellular matrix, called the basal lamina, underlies the dermis and separates it from tissues below.
E)Fibroblasts in the dermis produce extracellular matrix proteins to make the dermis strong and flexible.

Answer 3

D

Question 4

An epithelial tissue is defined as a:

A)collection of cells that lines cavities or outside surfaces.
B)collection of contractile cells.
C)network of cells that use chemical communication.
D)few cells embedded into an extensive extracellular matrix.

Question 5

Many scientists use a specific type of mouse cell to coat the surface of petri dishes. These cells form a layer on which other kinds of cells-often of different species-can adhere and grow. The mouse cells used to coat petri dishes are likely:

A)epidermal cells.
B)melanocytes.
C)hepatocytes.
D)fibroblasts.
E)microvilli.

Question 6

The area where the epidermis and the dermis meet is highly folded so that the epidermis "fits" into the dermis. What do you think is the function of this highly folded area?

A)Because the epidermis needs to send signals to the dermis, the highly folded area increases the surface area and hence the amount of signals that can reach the dermis.
B)Because the dermis needs to send signals to the epidermis, the highly folded area increases the surface area and hence the amount of signals that can reach the epidermis.
C)The epidermis is the outer layer and is under constant physical stress. This highly folded area between the epidermis and the dermis gives the epidermis additional support and protection against abrasive stress.
D)The epidermis needs to obtain melanin, the pigment produced by melanocytes, which are located in the dermis. The highly folded area increases the surface area and hence the amount of melanin that reaches the epidermis.

Question 7

Which of the following is NOT considered an epithelial tissue?

A)the epidermis of the skin
B)the lining of the stomach
C)the interior of the brain
D)the lining of the intestines
E)All of the answer options are examples of epithelial tissue.

Question 8

Which of the following structures are responsible for the shape of a cell?

A)microvilli
B)cytoskeleton
C)cell junctions
D)organelles

Question 9

The extracellular matrix is a network of:

A)proteins and polysaccharides inside the cell that keep organelles in place.
B)proteins and polysaccharides outside the cell that play a role in structural support.
C)proteins found in the cellular membrane that allow for substances to enter the cell.
D)channel proteins found in the cellular membrane that allow for communication.

Question 10

A pathologist is carrying out an autopsy. Upon opening the chest cavity, the pathologist sees a thick, fibrous tissue surrounding the heart. This is likely:

A)neural tissue.
B)epithelial tissue.
C)muscle tissue.
D)connective tissue.

Question 11

The epidermis contains several layers and receives its nutrients from the dermis by diffusion. Which of the following explains why the outermost layers of the epidermis consist of dead cells?

A)One of the major functions of the epidermis is forming a waterproof barrier. Once that barrier is formed, nutrients cannot pass through it and the cells beyond that layer die.
B)The protective function that the epidermis carries out is better served by having a layer of dead cells.
C)UV light cannot penetrate as easily through dead cells as it can through live cells.
D)None of the other answer options is correct.

Question 12

Cells differentiate into multiple tissue types because each tissue has its own unique DNA.

Question 13

Epithelial tissue is found:

A)on the outer surface of the body.
B)lining the gastrointestinal tract.
C)lining the lungs.
D)lining blood vessels.
E)All of these choices are correct.

Question 14

Many scientists are working to generate organs in vitro. In some cases, cells are seeded onto a "scaffold" shaped like the desired target organ. Such scaffolds are likely composed of extracellular matrix proteins.

Question 15

Which is the CORRECT order from lesser to greater complexity for the following?

A)organs, tissues, cells
B)cells, tissues, organs
C)tissues, organs, cells
D)cells, organs, tissues

Question 16

Which of the following tissues would you expect NOT to be found in the human heart?

A)muscle
B)nervous
C)epithelial
D)connective
E)All of these tissues would be found in the human heart.

Question 17

Structures known as microvilli are associated with:

A)communication between cells.
B)increased surface area for gas exchange.
C)adhesion to the extracellular matrix.
D)increased surface area for nutrient absorption.

Question 18

Which of the following statements about the skin is TRUE?

A)The epidermis is made up of epithelial tissue whereas the dermis is made up primarily of connective tissue.
B)The epidermis is made up of connective tissue whereas the dermis is made up primarily of epithelial tissue.
C)The epidermis and the dermis are made of the same tissue, called epithelial tissue.
D)The epidermis and the dermis are made of the same tissue, called connective tissue.

Question 19

The basal lamina is:

A)an area found beneath all connective tissues that helps them adhere to underlying muscle.
B)a specialized form of the extracellular matrix found beneath all epithelial tissues.
C)a specialized form of the extracellular matrix found only in the skin.
D)an area found wherever two different types of tissues meet.

Question 20

A researcher is studying a population of cells that are shaped normally, but appear to slide past one another. This is likely the result of mutations in genes encoding:

A)components of the extracellular matrix.
B)components of cell junctions.
C)components of the cytoskeleton.
D)components of microvilli.
E)components of both the extracellular matrix and cytoskeleton.

Question 21

Microtubules increase in length:

A)more quickly at one end than the other.
B)by growing outward from the centrosome.
C)in cycles, following rapid depolymerization.
D)if free tubulin dimers are available.
E)All of these choices are correct.

Question 22

Zebrafish embryos change the color of the melanophore cells in their skin to a darker shade by:

A)dynein motor proteins moving pigment granules outward from the center of the cell.
B)kinesin motor proteins moving pigment granules outward from the center of the cell.
C)dynein motor proteins moving pigment granules inward toward the center of the cell.
D)kinesin motor proteins moving pigment granules inward toward the center of the cell.
E)dynein motor proteins moving pigment granules inward toward the plus end of microtubules.

Question 23

Which of the following cytoskeletal elements contribute to the structural integrity and strength of epithelial tissues in animals?

A)intermediate filaments and microfilaments
B)intermediate filaments and microtubules
C)microtubules and microfilaments

Question 24

Microtubules and microfilaments are said to be "dynamic" elements of the cytoskeleton. In this case, "dynamic" means that:

A)once individual microfilaments and microtubules have formed, they can change shape and move around inside the cell.
B)they are constantly changing and are never in the same place for very long.
C)microtubules and microfilaments are assembled and disassembled and then reassembled again in a regulated manner.

Question 25

What would happen to a cell that depends on flagellar movement if it had no actin?

A)The cell would not be able to move because the cilia would also be affected.
B)The cell would not be able to move.
C)Nothing; the cell would still be able to move.
D)The cell would move by cilia and not flagella.

Question 26

Some cytoskeletal elements are more permanent than others. Which components of the cytoskeleton are dynamic structures?

A)microtubules
B)microfilaments
C)intermediate filaments
D)both microtubules and intermediate filaments
E)both microtubules and microfilaments

Question 27

Microfilaments increase in length:

A)more quickly at one end than the other.
B)by assembling outward from the centrosome.
C)in cycles, following rapid depolymerization.
D)if free tubulin dimers are available.
E)All of these choices are correct.

Question 28

Epidermolysis bullosa is a set of rare genetic disorders that is caused by:

A)a keratin gene that disrupts intermediate filaments, weakening epidermal cell connections.
B)a microfilament gene that disrupts desmosomes, weakening epidermal cell connections.
C)an intermediate filament gene that disrupts hemidesmosomes, weakening epidermal cell connections.
D)a keratin gene that disrupts microfilaments, weakening epidermal cell connections.
E)All of these choices are correct.

Question 29

Dynein motor proteins use ATP to:

A)carry vesicles along a microtubule within a cell in a minus-to-plus direction.
B)carry vesicles along a microfilament within a cell in a minus-to-plus direction.
C)carry vesicles along a microtubule within a cell in a plus-to-minus direction.
D)carry vesicles along a microfilament within a cell in a plus-to-minus direction.
E)slide along microfilaments to contract muscle cells.

Question 30

Dynamic instability of microtubules:

A)is caused by the large size of this type of cytoskeletal element.
B)results from a deficiency of free tubulin subunits.
C)allows microtubules to perform their functions.
D)is shared by no other cytoskeletal elements.
E)All of these choices are correct.

Question 31

Myosin motor proteins use ATP to:

A)carry vesicles along a microtubule within a cell in a minus-to-plus direction.
B)carry vesicles along a microfilament within a cell in a minus-to-plus direction.
C)carry vesicles along a microtubule within a cell in a plus-to-minus direction.
D)carry vesicles along a microfilament within a cell in a plus-to-minus direction.
E)slide along intermediate filaments to contract muscle cells.

Question 32

The cytoskeleton of animal cells includes:

A)microtubules, microfilaments, and intermediate filaments.
B)actin, microfilaments, and intermediate filaments.
C)actin, microtubules, and intermediate filaments.
D)tubulin, microfilaments, and intermediate filaments.
E)microtubules and microfilaments.

Question 33

A tissue is generally composed of several organs.

Question 34

Which one of the following statements about connective tissue is TRUE?

A)Connective tissue is very cell dense.
B)Connective tissue lacks a strong extracellular matrix.
C)Cells composing connective tissue typically have microvilli.
D)Connective tissue cells are typically multinucleate.
E)None of the other answer options is correct.

Question 35

What would happen in a cell if its a-tubulin was mutated and unable to bind to its b tubulin?

A)The cell would have no microfilaments.
B)The cell would have no microtubules.
C)The cell would be unaffected.
D)The cell would have no intermediate filaments.

Question 36

Which one of the following statements about intracellular transport is TRUE?

A)Microtubules and microfilaments facilitate cellular movement, but intermediate filaments do not.
B)Microtubules and intermediate filaments facilitate cellular movement, but microfilaments do not.
C)Intermediate filaments and microfilaments facilitate cellular movement, but microtubules do not.
D)Intermediate filaments, microfilaments, and microtubules all facilitate cellular movement of one kind or another.

Question 37

A researcher is assessing the expression of a certain protein in cells. This protein appears as a "web" in the cytoplasm of cells. The protein is likely a component of:

A)the cytoskeleton.
B)cell junctions.
C)the extracellular matrix.
D)of the basal lamina.
E)All of these choices are correct.

Question 38

Cilia and flagella:

A)are specialized cells that move by rotary motion.
B)are specialized organelles that move by rotary motion.
C)are specialized organelles that propel some algae, plant, and animal cells.
D)contain microfilaments arranged in nine pairs around the periphery and two microfilaments in the center.
E)contain microtubules arranged in nine pairs around the periphery and two microfilaments in the center.

Question 39

Which of the following statements about intracellular transport is TRUE?

A)Kinesin and myosin move substances toward the "plus end" of microtubules and microfilaments, respectively.
B)Kinesin and myosin move substances toward the "minus end" of microtubules and microfilaments, respectively.
C)Myosin and kinesin move substances toward the "plus end" of microtubules and microfilaments, respectively.
D)Myosin and kinesin move substances toward the "minus end" of microtubules and microfilaments, respectively.

Question 40

Imagine that you are examining a mouse that does not produce basal lamina in the skin. How will this mouse be different from a normal, wild-type mouse?

A)The epidermis will not be connected to the dermis.
B)The epidermis and dermis will be strongly connected.
C)The dermis will be disorganized and will lack blood vessels.
D)Cellular junctions will fail to form between the cells of the epidermis.
E)All of these choices are correct.

Question 41

Which of the following is NOT an example of an intermediate filament protein?

A)keratin
B)actin
C)lamin
D)vimentin

Question 42

If cells did not have actin, they would be unable to:

A)organize proteins across the cytoplasmic membrane.
B)maintain shape.
C)connect to neighboring cells.
D)All of these choices are correct.

Question 43

Which one of the following cytoskeletal elements is associated with supporting the movement of materials inside the cell?

A)microtubules
B)microfilaments
C)intermediate filaments
D)both microtubules and microfilaments

Question 44

The cytoskeleton of plant cells includes:

A)microtubules, microfilaments, and intermediate filaments.
B)actin, microfilaments, and intermediate filaments.
C)actin, microtubules, and intermediate filaments.
D)tubulin, microfilaments, and intermediate filaments.
E)microtubules and microfilaments.

Question 45

Evidence that cytoskeletal elements have ancient origins comes from the:

A)sequence similarities of cytoskeletal elements when comparing distantly related organisms.
B)presence of cytoskeletal elements in both eukaryotes and prokaryotes.
C)observation that both prokaryotes and eukaryotes use cytoskeletal elements to assist cell division.
D)ability to form functional hybrid microfilaments from actin monomers taken from distantly related organisms.
E)All of these choices are correct.

Question 46

Dynamic instability is the rapid assembly and disassembly of:

A)microfilaments.
B)intermediate filaments.
C)microtubules.
D)both microfilaments and microtubules.

Question 47

Which is the correct order of cytoskeletal filaments in DECREASING filament diameter?

A)microfilaments $\rightarrow$ microtubules $\rightarrow$ intermediate filaments
B)microtubules $\rightarrow$ intermediate filaments $\rightarrow$ microfilaments
C)microtubules $\rightarrow$ microfilaments $\rightarrow$ intermediate filaments
D)intermediate filaments $\rightarrow$ microfilaments $\rightarrow$ microtubules

Question 48

Why are the ends of microfilaments and microtubules called "plus ends" and "minus ends"?

A)Because monomers are added more quickly to one end (the "plus end")than they are to the other end (the "minus end").
B)Because polymerization occurs at one end (the "plus end")and depolymerization occurs at the other end (the "minus end").
C)Because monomers can be added to one end only (the "plus end"), and can only be removed from the other end (the "minus end").
D)Because the actin and tubulin monomers that make up microfilaments and microtubules have evolved more rapidly than most other proteins.

Question 49

Cilia are:

A)specialized organelles found in some epithelial cells.
B)used by epithelial cells to move substances along cell surfaces.
C)used by sperm cells for locomotion.
D)None of the other answer options is correct.

Question 50

Which is NOT an example of a motor protein?

A)myosin
B)kinesin
C)venosin
D)dynein

Question 51

Which one of the cytoskeletal elements is associated with providing the cell with mechanical strength?

A)microtubules
B)microfilaments
C)microtubules and microfilaments
D)intermediate filaments

Question 52

What is the BEST characterization of the minus end of a dynamic filament?

A)It is fast growing.
B)It is slow growing.
C)It loses subunits quickly.
D)It is slow growing, and also loses its subunits quickly.

Question 53

Intermediate filaments:

A)have a diameter that is larger than a microfilament, but smaller than a microtubule.
B)play an important role in maintaining cell shape.
C)play an important role in preventing skin from tearing by shear stress.
D)undergo little change in length in comparison to microtubules and microfilaments.
E)All of these choices are correct.

Question 54

Kinesin motor proteins use ATP to:

A)carry vesicles along a microtubule within a cell in a minus-to-plus direction.
B)carry vesicles along a microfilament within a cell in a minus-to-plus direction.
C)carry vesicles along a microtubule within a cell in a plus-to-minus direction.
D)carry vesicles along a microfilament within a cell in a plus-to-minus direction.
E)slide along microfilaments to contract muscle cells.

Question 55

Which one of the following statements about intracellular transport is TRUE?

A)Kinesin and myosin move substances along microtubules.
B)Kinesin and dynein move substances along microfilaments.
C)Myosin and dynein move substances along microfilaments.
D)Myosin moves substances along microfilaments.

Question 56

Cells with cilia or flagella rely mainly on _____ to facilitate their movement.

A)microtubules
B)microfilaments
C)intermediate filaments

Question 57

Which one of the following statements about intracellular transport is TRUE?

A)Kinesin and dynein move substances along microtubules.
B)Kinesin and myosin move substances along microtubules.
C)Kinesin and dynein move substances along microfilaments.
D)Kinesin moves substances along microfilaments.

Question 58

Which one of the following is NOT a cellular function associated with microtubules?

A)muscle contraction
B)chromosome segregation
C)organization of organelles
D)movement of cilia and flagella

Question 59

Flagella move in a(n):

A)oarlike motion by the motor protein dynein sliding microtubules past each other.
B)oarlike motion by the motor protein kinesin sliding microtubules past each other.
C)whiplike motion by the motor protein dynein sliding microtubules past each other.
D)whiplike motion by the motor protein kinesin sliding microtubules past each other.
E)whiplike motion by the motor protein dynein sliding microfilaments past each other.

Question 60

Dynamic instability is a:

A)feature of microtubules.
B)feature of microfilaments.
C)feature of intermediate filaments.
D)feature of microtubules and microfilaments.
E)universal feature of the cytoskeleton.

Question 61

Why do you think the presence of a specific type of keratin, an intermediate filament protein, in the bloodstream or lymph node is an indicator of metastasis of tumor cells?

A)Intermediate filaments are only found in tumor cells.
B)Keratin is only present if its specific cell type is also present.
C)Intermediate filament proteins cause cells to clump together.
D)None of the other answer options is correct.

Question 62

The property of dynamic instability implies that the individual protein subunits of microtubules are held together by:

A)covalent bonds.
B)disulfide bonds.
C)noncovalent interactions.
D)All of these choices are correct.

Question 63

Which of the following is a FALSE statement about the motor proteins myosin and kinesin?

A)They both use ATP.
B)They both move cargo to the plus end of a cytoskeletal filament.
C)They both move along microtubules.
D)None these statements about myosin and kinesin is false.

Question 64

If a mutation occurred in the cadherin gene so that the cytoplasmic domain no longer attached to the cytoskeleton, which of the following would occur?

A)Cadherins in desmosomes would no longer be anchored to intermediate filaments.
B)Cadherins in adherens junctions would no longer be anchored to microtubules.
C)Cadherins in hemidesmosomes would no longer be anchored to intermediate filaments.
D)Cadherins in desmosomes would no longer be anchored to microfilaments.

Question 65

Which one of the following is NOT a cellular function of microfilaments?

A)flagellar movement
B)transport of vesicles
C)muscle contraction
D)formation of daughter cells following mitosis

Question 66

Macrophage cells undergo a process called phagocytosis in which material is brought into a cell in the form of membrane vesicles and then transported along microtubules toward the cell center. Assuming that the centrosome is near the cell center, you can predict that these vesicles are moving to the _____ end of microtubules using the motor protein _____.

A)minus end; kinesin
B)plus end; kinesin
C)minus end; dynein
D)plus end; dynein

Question 67

Dynein is a motor protein found attached to:

A)lamin.
B)microfilaments.
C)microtubules.
D)intermediate filaments.

Question 68

Could an isolated melanin granule move along an actin microfilament?

A)Yes, melanin granules have motor proteins.
B)Yes, motor proteins all use ATP to cause a conformation change.
C)No, motor proteins are specific for the type of filament they bind.
D)None of the other answer options is correct.

Question 69

Which one of the following is a characteristic shared by integrins and cadherins?

A)Both are peripheral membrane proteins.
B)Both facilitate the adhesion of cells to extracellular matrix proteins.
C)Both are present in adherens junctions, desmosomes, and hemidesmosomes.
D)The cytoplasmic domains of both proteins are connected to the cytoskeleton.

Question 70

In nerve cells, the centrosome is located near the nucleus. Vesicles move from near the nucleus to the end of long extensions (axons) along microtubules. Based on these two facts, it is possible to conclude that these vesicles are moving in the _____ direction on the microtubule using the motor protein _____.

A)minus end; dynein
B)plus end; kinesin
C)minus end; kinesin
D)plus end; dynein

Question 71

The internal cytoskeletal structure of cilia and flagella grows out from a structure called a basal body located near the cell surface. Based on this information, where would you predict the plus end of the microtubules to be located?

A)near the basal body
B)near the tip of the cilia or flagella
C)at both ends of the cilia or flagella
D)It is not possible to predict from the information provided.

Question 72

If intermediate filaments were capable of dynamic instability, which of the following outcomes would be MOST likely?

A)Cell adhesion would be affected.
B)Cilia would be altered.
C)Chromosome segregation would be affected.
D)Microvilli would collapse.
E)It is not possible to determine the outcome from the information given.

Question 73

Which one of the following properly groups a cell junction with a cytoskeletal element and a cell adhesion molecule?

A)adherens junction, microfilament, integrin
B)hemidesmosome, microfilament, cadherin
C)desmosome, intermediate filament, cadherin
D)hemidesmosome, intermediate filament, cadherin

Question 74

Red blood cells are characterized as having an actin cytoskeleton associated with their plasma membrane. The presence of the membrane cytoskeleton MOST likely accounts for:

A)the shape of the cell.
B)enhanced gas exchange.
C)the ability of these cells to fit through narrow capillaries.
D)All of these choices are correct.

Question 75

Which one of the following properly groups a cell junction with a cytoskeletal element and cell adhesion molecule?

A)desmosome, microtubule, integrin
B)desmosome, microfilament, integrin
C)tight junction, cadherin, intermediate filament
D)adherens junction, microfilament, cadherin

Question 76

Myosin is a motor protein that associates with:

A)microfilaments.
B)microtubules.
C)intermediate filaments.
D)vimentin.

Question 77

Which of the following cytoskeletal elements is capable of assembling and disassembling in the cell?

A)microtubules
B)intermediate filaments
C)microfilaments
D)both microtubules and microfilaments

Question 78

Motor proteins cause movement by: (1) undergoing a conformational change, (2) harnessing energy from ATP, and (3) binding to the cytoskeleton.

A)Statements (1), (2), and (3)are correct.
B)Statements (1)and (2)are correct.
C)Statements (1)and (3)are correct.
D)Statements (2)and (3)are correct.

Question 79

Which motor protein(s) would you find in a flagellum?

A)myosin
B)dynein
C)kinesin
D)both myosin and dynein

Question 80

Kinesin is a motor protein found attached to:

A)microfilaments.
B)microtubules.
C)intermediate filaments.
D)tubulin.