BLY CH 10 Learning Curve

The extracellular matrix can influence the shape of a cell because: (1) cell adhesion proteins on the plasma membrane attach to the extracellular matrix; (2) cell adhesion proteins attach to the cell's cytoskeleton; (3) the cytoskeleton determines cell shape. Statement (1) is correct. Statement (2) is correct. Statement (1) and (2) are correct. Statement (3) is correct. All of the statements are correct.

All of the statements are correct.

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: the shape of the cell. enhanced gas exchange. the ability of these cells to fit through narrow capillaries. All of these choices are correct.

All of these choices are correct.

What is the advantage of forcing materials to travel through cells instead of between cells? Exposure to bacteria or viruses is limited. Cells can control which materials are transported. Exposure to toxins is limited. All of these choices are correct.

All of these choices are correct.

What would you expect to find within connective tissue? elastin All of these choices are correct. polysaccharides collagen fibroblasts

All of these choices are correct.

Could an isolated melanin granule move along an actin microfilament? No, motor proteins are specific for the type of filament they bind. None of the other answer options is correct. Yes, melanin granules have motor proteins. Yes, motor proteins all use ATP to cause a conformation change.

No, motor proteins are specific for the type of filament they bind.

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? UV light cannot penetrate as easily through dead cells as it can through live cells. 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. The protective function that the epidermis carries out is better served by having a layer of dead cells. None of the other answer options is correct.

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.

The extracellular matrix is composed of: (1) proteins; (2) polysaccharides; (3) nucleic acids. Statement (1) is correct. Statements (1) and (2) are correct. Statement (2) is correct. All of these statements are correct. Statement (3) is correct.

Statements (1) and (2) are correct.

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. FALSE TRUE

TRUE

Predict what would happen if an embryonic epidermal cell switched from expressing E-cadherin to N-cadherin. The cell would become a neural cell. The cell would leave the epidermis and join the neural cells. The cell would die. There would be no effect.

The cell would leave the epidermis and join the neural cells.

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? 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. 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. 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. 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.

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.

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? The epidermis and dermis will be strongly connected. The dermis will be disorganized and will lack blood vessels. All of these choices are correct. Cellular junctions will fail to form between the cells of the epidermis.

The epidermis will not be connected to the dermis.

Gap junctions and plasmodesmata have what feature in common? They both attach to the cytoskeleton. They both are made up of protein subunits located in the plasma membrane. They both allow direct transport of materials between cells. They are both found in plant cells.

They both allow direct transport of materials between cells.

Which of the following is a false statement about the motor proteins myosin and kinesin? Please choose the correct answer from the following choices, and then select the submit answer button. They both use ATP. They both move cargo to the plus end of a cytoskeletal filament. They both move along microtubules. None these statements about myosin and kinesin is false.

They both move cargo to the plus end of a cytoskeletal filament.

Cadherin is an example of: a motor protein. a cell adhesion molecule. an intermediate filament protein. an extracellular matrix protein.

a cell adhesion molecule.

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 the basal lamina. a component of the cytoskeleton. a component of cell junctions. a component of the extracellular matrix. All of these choices are correct.

a component of the cytoskeleton.

The basal lamina is: an area found beneath all connective tissues that help them adhere to underlying muscle. a specialized form of the extracellular matrix found only in the skin. a specialized form of the extracellular matrix found beneath all epithelial tissues. an area found wherever two different types of tissues meet.

a specialized form of the extracellular matrix found beneath all epithelial tissues.

Microvilli are located on the ______ of a cell. adjacent surface basolateral surface basement membrane apical surface

apical surface

Which of the following cytoskeletal elements is capable of assembling and disassembling in the cell? microtubules microfilaments intermediate filaments both microtubules and microfilaments

both microtubules and microfilaments

Which one of the following cytoskeletal elements is associated with supporting the movement of materials inside the cell? microtubules microfilaments intermediate filaments both microtubules and microfilaments

both microtubules and microfilaments

The natural loss of dead cells from the surface of your skin is a result of: loss of adherens junctions between epithelial cells. breakdown of desmosomes. loss of microvilli. both the loss of adherens junctions between epithelial cells, and the breakdown of desmosomes.

both the loss of adherens junctions between epithelial cells, and the breakdown of desmosomes.

If intermediate filaments were capable of dynamic instability, which of the following outcomes would be most likely? cell adhesion would be affected cilia would be altered microvilli would collapse chromosome segregation would be affected It is not possible to determine the outcome from the information given.

cell adhesion would be affected

Which of the following is a component of the extracellular matrix made by a plant cell? cellulose. collagen. cadherin. All of these choices are correct.

cellulose.

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: components of both the extracellular matrix and cytoskeleton. components of cell junctions. components of the extracellular matrix. components of the cytoskeleton. components of microvilli.

components of cell junctions.

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: hepatocytes. epidermal cells. microvilli. melanocytes. fibroblasts.

fibroblasts.

Which one of the following is not a cellular function of microfilaments? flagellar movement formation of daughter cells following mitosis transport of vesicles muscle contraction

flagellar movement

Structures known as microvilli are associated with: communication between cells. increased surface area for gas exchange. increased surface area for nutrient absorption. adhesion to the extracellular matrix.

increased surface area for nutrient absorption.

In skin, the cells of the epidermis connect to the basal lamina through cellular junctions known as hemidesmosomes. Select the cytoskeletal element that helps maintain the integrity of this connection. microtubules intermediate filaments microfilaments both intermediate filaments and microfilaments

intermediate filaments

Which one of the cytoskeletal elements is associated with providing the cell with mechanical strength? microtubules intermediate filaments microfilaments microtubules and microfilaments

intermediate filaments

Which is the correct order of cytoskeletal filaments in decreasing filament diameter? microfilaments %u2192 microtubules %u2192 intermediate filaments microtubules %u2192 intermediate filaments %u2192 microfilaments microtubules %u2192 microfilaments %u2192 intermediate filaments intermediate filaments %u2192 microfilaments %u2192 microtubules

microtubules %u2192 intermediate filaments %u2192 microfilaments

Kinesin is a motor protein found attached to: intermediate filaments. microfilaments. microtubules. tubulin.

microtubules.

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 _____. minus end; kinesin plus end; dynein plus end; kinesin minus end; dynein

minus end; dynein

Which one of the following is not a cellular function associated with microtubules? organization of organelles muscle contraction chromosome segregation movement of cilia and flagella

muscle contraction

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 _____. minus end; dynein plus end; kinesin minus end; kinesin plus end; dynein

plus end; kinesin

The most likely reason(s) a metastatic tumor cell might lose its connection to the basal lamina would be: the loss of integrin proteins from the cell's surface, or a change in the type of integrin proteins present on the cell's surface. a change in the type of integrin proteins present on the cell's surface. a change in the composition of the basal lamina. the loss of integrin proteins from the cell's surface.

the loss of integrin proteins from the cell's surface, or a change in the type of integrin proteins present on the cell's surface.

How do cells connect to the extracellular matrix? Please choose the correct answer from the following choices, and then select the submit answer button. through gap junctions through cadherins through integrins through tight junctions

through integrins