Question 1

Refer to the figure below.  The type of cell junction shown is most efficient in

Accepted Answer

The answer of Refer to the figure below.  The...

Question 2

Scientists have been able to engineer young laboratory mice to have a defective gene for a particular integrin protein only in epidermal skin cells.These mice develop into adults with severe hair loss and skin blistering.Which statement explains the connection between the mutation and the observed physical problems of the mice?

Accepted Answer

Integrins are proteins that mediate the attachment of cells to the extracellular matrix. A defective gene for an integrin protein in epidermal cells would impair the ability of these cells to adhere properly to the extracellular matrix, leading to skin blistering and potentially affecting hair follicle stability, resulting in hair loss.

Question 3

Cell adhesion occurs through the interactions of

Accepted Answer

Cell adhesion typically occurs through the interactions of glycoproteins and glycolipids on the cell surface. These molecules can recognize and bind to specific complementary molecules on another cell or extracellular matrix, allowing for cell-cell and cell-substrate adhesion.

Question 4

Which type of molecule can function as a recognition signal for interactions between cells?

Accepted Answer

Glycolipids are molecules composed of carbohydrates and lipids that are found on the surface of cells. They can function as recognition signals for interactions between cells, as they can be recognized by other cells or molecules in the body. This recognition is important for various cellular processes, such as immune responses and embryonic development.

Question 5

Integrin on the cell surface of a white blood cell binds reversibly with the extracellular matrix of blood vessel walls.This reversibility allows for

Accepted Answer

The reversibility of integrin binding allows for cell movement, specifically the ability for white blood cells to migrate out of blood vessels and to sites of infection or injury.

Question 6

Refer to the figure below.  The type of cell junction shown is most efficient in

Accepted Answer

The type of cell junction shown in the figure is a tight junction or occluding junction, which forms a continuous barrier between cells and prevents the leakage of molecules and ions between cells. This makes it an efficient junction for epithelial cells that line animal body cavities, such as the lining of the digestive tract, urinary tract, and blood vessels, where there is a need to maintain a selective barrier to regulate the exchange of molecules between the lumen and the underlying tissues.

Question 7

Heart muscle cells beat in unison because of the rapid spread of electrical current through

Accepted Answer

Gap junctions allow for the rapid spread of electrical current between heart muscle cells, allowing them to beat in unison.

Question 8

You are monitoring the diffusion of a molecule across a membrane.Of the options listed below, the fastest rate of diffusion would result from an internal concentration of _______ $\mu$M and an external concentration of _______ $\mu$M.

Accepted Answer

The rate of diffusion across a membrane is fastest when the concentration gradient is the largest, meaning the difference between the internal and external concentrations is greatest. Option A, with an internal concentration of 5 and an external concentration of 60, presents the largest concentration gradient among the choices.

Question 9

You are working in a lab that is studying cell recognition and cell attachment in a red sponge.You need to culture individual cells in a medium that promotes cell recognition and attachment of isolated cells.Which of the following would you add to the culture medium?

Accepted Answer

Species-specific polysaccharides are often involved in cell recognition and attachment processes, as they can provide the necessary signals for cells to recognize and adhere to each other.

Question 10

Osmosis is a specific form of

Accepted Answer

Osmosis is a type of diffusion, specifically the movement of water molecules from an area of high concentration to an area of low concentration across a semi-permeable membrane. Facilitated transport, active transport, and secondary active transport all require the use of carrier proteins, while osmosis does not require a carrier protein.

Question 11

Two membrane components that serve as cell recognition sites are

Accepted Answer

Glycolipids and glycoproteins are membrane components that have carbohydrate chains attached to them. These carbohydrate chains can act as cell recognition sites, allowing cells to identify and interact with each other.

Question 12

Sponges are multicellular organisms whose bodies allow water to circulate freely.If isolated cells from one species were added to a solution of isolated cells from another species, what would you expect in terms of binding among the cells?

Accepted Answer

In sponges, cell recognition and binding occur only between cells of the same species. Therefore, cells from one species would bind only to others of the same species.

Question 13

A student claims that cell recognition and cell adhesion refer to the same function.Which statement best evaluates this claim?

Accepted Answer

While cell adhesion is based on the complementary surfaces of molecules on different cells, these molecules must first be recognized in order for cell adhesion to occur. Cell recognition is therefore a necessary prerequisite for cell adhesion, but the two functions are not interchangeable. Additionally, cell recognition plays a role in many other functions beyond just adhesion.

Question 14

In animal cell junctions, _______ seal intercellular spaces, _______ reinforce attachments, and _______ allow for communication between cells.

Accepted Answer

Tight junctions seal intercellular spaces, desmosomes reinforce attachments, and gap junctions allow for communication between cells. Keratins are intermediate filaments, not junction proteins. Cell recognition molecules are involved in cell signaling and recognition, but not in junctions. Adhesion molecules are important for cell-cell interactions, but not necessarily in junctions. Connexins are specifically involved in gap junctions, but not in tight or desmosome junctions. Therefore, the best choice is B.

Question 15

A group of transmembrane proteins involved in maintaining animal cell structure via their interactions with the cytoskeleton are known as

Accepted Answer

Integrins are transmembrane proteins that play a crucial role in cell adhesion, connecting the cell's cytoskeleton with the extracellular matrix. This interaction is essential for maintaining the structural integrity of tissues.

Question 16

You are studying the effects of different substances on frog heart muscle cells.You treat the cells with a substance that blocks gap junctions.What do you expect will occur?

Accepted Answer

Gap junctions are channels that allow for the transfer of electrical current between adjacent cells, such as in heart muscle cells. Blocking these gap junctions would prevent the even spread of electrical current between cells, potentially leading to arrhythmias or other disruptions in heart function.

Question 17

If tight junctions were replaced by desmosomes in cells lining the bladder,

Accepted Answer

Desmosomes provide strong adhesion between cells but do not seal intercellular spaces, allowing dissolved substances to move freely through the extracellular matrix.

Question 18

Which factor does not affect the rate of diffusion of a substance?

Accepted Answer

The presence of other solutes in the solution do not affect the rate of diffusion of a substance. The rate of diffusion is only affected by the temperature of the solution, concentration gradient, density of the solution, and molecular diameter of the diffusing material.

Question 19

Which is the name of a specialized cell junction that allows rapid spread of electric current via the flow of ions between animal cells?

Accepted Answer

Gap junctions are specialized cell junctions that allow for the rapid spread of electric current via the flow of ions between animal cells. They are formed by connexin proteins and are commonly found in tissues that require fast electrical communication, such as cardiac and smooth muscle. Tight junctions and desmosomes are types of cell junctions that are involved in cell adhesion and tissue integrity, but do not allow for the flow of ions between cells. Integrins are transmembrane proteins that serve as receptors for extracellular molecules and are involved in cell signaling and adhesion.

Question 20

A biologist hypothesizes that a particular membrane protein is distributed throughout the cell and anchored to the cytoskeleton.Which experimental technique could provide evidence to test the biologist's hypothesis, and why?

Accepted Answer

The answer of A biologist hypothesizes that a particular membrane...

Quiz 6: Cell Membranes

Refer to the figure below. The type of cell junction shown is most efficient in

Cell adhesion occurs through the interactions of

Which type of molecule can function as a recognition signal for interactions between cells?

Integrin on the cell surface of a white blood cell binds reversibly with the extracellular matrix of blood vessel walls.This reversibility allows for

Refer to the figure below. The type of cell junction shown is most efficient in

Heart muscle cells beat in unison because of the rapid spread of electrical current through

You are monitoring the diffusion of a molecule across a membrane.Of the options listed below, the fastest rate of diffusion would result from an internal concentration of _ $\mu$ M and an external concentration of _ $\mu$ M.

You are working in a lab that is studying cell recognition and cell attachment in a red sponge.You need to culture individual cells in a medium that promotes cell recognition and attachment of isolated cells.Which of the following would you add to the culture medium?

Osmosis is a specific form of

Two membrane components that serve as cell recognition sites are

Sponges are multicellular organisms whose bodies allow water to circulate freely.If isolated cells from one species were added to a solution of isolated cells from another species, what would you expect in terms of binding among the cells?

A student claims that cell recognition and cell adhesion refer to the same function.Which statement best evaluates this claim?

In animal cell junctions, ___ seal intercellular spaces, _ reinforce attachments, and _____ allow for communication between cells.

A group of transmembrane proteins involved in maintaining animal cell structure via their interactions with the cytoskeleton are known as

You are studying the effects of different substances on frog heart muscle cells.You treat the cells with a substance that blocks gap junctions.What do you expect will occur?

If tight junctions were replaced by desmosomes in cells lining the bladder,

Which factor does not affect the rate of diffusion of a substance?

Which is the name of a specialized cell junction that allows rapid spread of electric current via the flow of ions between animal cells?

A biologist hypothesizes that a particular membrane protein is distributed throughout the cell and anchored to the cytoskeleton.Which experimental technique could provide evidence to test the biologist's hypothesis, and why?

Quiz 6: Cell Membranes

Refer to the figure below. The type of cell junction shown is most efficient in

Cell adhesion occurs through the interactions of

Which type of molecule can function as a recognition signal for interactions between cells?

Integrin on the cell surface of a white blood cell binds reversibly with the extracellular matrix of blood vessel walls.This reversibility allows for

Refer to the figure below. The type of cell junction shown is most efficient in

Heart muscle cells beat in unison because of the rapid spread of electrical current through

You are monitoring the diffusion of a molecule across a membrane.Of the options listed below, the fastest rate of diffusion would result from an internal concentration of _______ μ\muμ M and an external concentration of _______ μ\muμ M.

You are working in a lab that is studying cell recognition and cell attachment in a red sponge.You need to culture individual cells in a medium that promotes cell recognition and attachment of isolated cells.Which of the following would you add to the culture medium?

Osmosis is a specific form of

Two membrane components that serve as cell recognition sites are

Sponges are multicellular organisms whose bodies allow water to circulate freely.If isolated cells from one species were added to a solution of isolated cells from another species, what would you expect in terms of binding among the cells?

A student claims that cell recognition and cell adhesion refer to the same function.Which statement best evaluates this claim?

In animal cell junctions, _______ seal intercellular spaces, _______ reinforce attachments, and _______ allow for communication between cells.

A group of transmembrane proteins involved in maintaining animal cell structure via their interactions with the cytoskeleton are known as

You are studying the effects of different substances on frog heart muscle cells.You treat the cells with a substance that blocks gap junctions.What do you expect will occur?

If tight junctions were replaced by desmosomes in cells lining the bladder,

Which factor does not affect the rate of diffusion of a substance?

Which is the name of a specialized cell junction that allows rapid spread of electric current via the flow of ions between animal cells?

A biologist hypothesizes that a particular membrane protein is distributed throughout the cell and anchored to the cytoskeleton.Which experimental technique could provide evidence to test the biologist's hypothesis, and why?

You are monitoring the diffusion of a molecule across a membrane.Of the options listed below, the fastest rate of diffusion would result from an internal concentration of _ $\mu$ M and an external concentration of _ $\mu$ M.

In animal cell junctions, ___ seal intercellular spaces, _ reinforce attachments, and _____ allow for communication between cells.