Question 1

Myosin is a motor protein that associates with:

Accepted Answer

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

Question 2

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

Accepted Answer

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

Question 3

In many cells, the adhesion to the extracellular matrix through integrins causes the activation of kinases in the cytoplasm. This suggests that:

Accepted Answer

A) integrins promote the activation of signal-transduction pathways. 
B) integrins are kinases. 
C) extracellular matrix proteins are receptors and integrins are ligands.

Question 4

The extracellular matrix is particularly important for which type of tissue?

Accepted Answer

A) epithelial 
B) muscle 
C) connective 
D) nervous

Question 5

Which of the following is associated with microtubules?

Accepted Answer

A) desmosomes 
B) adherens junction 
C) cilia and flagella

Question 6

Suppose that frog embryos are genetically manipulated so that the epidermal cells expressed both E-cadherin and N-cadherin on their cell surface. The neuronal tissue and epidermal tissues are collected from the embryos and treated as illustrated in Figure 10.12b. Which of the following would you predict would happen now that N-cadherin is also present on the surface of the epidermal cells?

Accepted Answer

A) The genetically modified epidermal cells would adhere to each other and to neuronal cells. 
B) The genetically modified epidermal cells would adhere to neuronal cells and would no longer adhere to epidermal cells. 
C) The genetically modified epidermal cells would adhere to each other, and not to the neuronal cells, because they would still be epidermal cells regardless of the presence of an additional cell adhesion protein on their surface.

Question 7

What is the advantage of forcing materials to travel through cells instead of between cells?

Accepted Answer

A) Cells can control which materials are transported. 
B) Exposure to toxins is limited. 
C) Exposure to bacteria or viruses is limited. 
D) All of these choices are correct.

Question 8

Microtubules increase in length:

Accepted Answer

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 9

Keratinocytes are pigment cells contained in the epidermis of skin.

Accepted Answer

A) True 
 B)False

Question 10

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

Accepted Answer

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

Question 11

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:

Accepted Answer

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

Question 12

Epithelial tissue is found:

Accepted Answer

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 13

A tissue is generally composed of several organs.

Accepted Answer

A) True 
 B)False

Question 14

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

Accepted Answer

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 15

Some cell junctions allow materials to pass between adjacent cells so that they work together as a unit.

Accepted Answer

A) True 
 B)False

Question 16

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

Accepted Answer

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

Question 17

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 cellsF1F1F1S1F1F1F10often of different speciesF1F1F1S1F1F1F10can adhere and grow. The mouse cells used to coat petri dishes are likely:

Accepted Answer

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

Question 18

Which one of the following statements about integrins is CORRECT?

Accepted Answer

A) Integrins indirectly connect microfilaments with the extracellular matrix. 
B) There is a single type of integrin, capable of binding to multiple types of extracellular matrix proteins. 
C) Integrins are the primary cell adhesion molecule in a desmosome. 
D) Adjacent integrins create channels referred to as gap junctions.

Question 19

Evidence that cytoskeletal elements have ancient origins comes from the:

Accepted Answer

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 20

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

Accepted Answer

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.

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

Myosin is a motor protein that associates with:

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

In many cells, the adhesion to the extracellular matrix through integrins causes the activation of kinases in the cytoplasm. This suggests that:

The extracellular matrix is particularly important for which type of tissue?

Which of the following is associated with microtubules?

What is the advantage of forcing materials to travel through cells instead of between cells?

Microtubules increase in length:

Keratinocytes are pigment cells contained in the epidermis of skin.

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

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:

Epithelial tissue is found:

A tissue is generally composed of several organs.

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

Some cell junctions allow materials to pass between adjacent cells so that they work together as a unit.

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

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:

Which one of the following statements about integrins is CORRECT?

Evidence that cytoskeletal elements have ancient origins comes from the:

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