Question 1

Which of the following statements best describes the function of the plasma membrane in a typical animal cell?

Accepted Answer

It is the outermost barrier of the cell, selectively regulating the cell's chemical environment.

Question 2

According to the fluid mosaic model, which of the following is TRUE about biological membranes?

Accepted Answer

Proteins are embedded within the lipid bilayer and can move laterally.

Question 3

Which factor would most likely increase the fluidity of a cell membrane?

Accepted Answer

Increasing the proportion of unsaturated fatty acids in the membrane lipids.

Question 4

A red blood cell is placed in a hypotonic solution. What is the most likely outcome?

Accepted Answer

Water will move into the cell, causing it to swell and possibly burst.

Question 5

Which equation best represents the net movement of molecules during diffusion across a concentration gradient?

Accepted Answer

$$J = -D \frac{dC}{dx}$$

Question 6

Which of the following is NOT a function of membrane proteins?

Accepted Answer

Providing the main structural support for the cell wall

Question 7

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

Facilitated diffusion involves specific carrier or channel proteins.

Question 8

Which of the following best describes selective permeability of the plasma membrane?

Accepted Answer

Some substances cross more easily than others due to membrane properties.

Question 9

A cell is placed in a hypertonic environment. What will happen to the cell?

Accepted Answer

Water will move out of the cell, causing it to shrink.

Question 10

Which of the following is a requirement for passive transport to occur across a biological membrane?

Accepted Answer

There must be a concentration gradient across the membrane.

Question 11

Which of the following best explains why oxygen can diffuse freely across the plasma membrane?

Accepted Answer

Oxygen is a small nonpolar molecule.

Question 12

Which of the following is TRUE about channel proteins in the plasma membrane?

Accepted Answer

They allow specific molecules to pass through by forming pores.

Question 13

Which of the following scenarios best illustrates the concept of a concentration gradient?

Accepted Answer

A cell with a higher concentration of sodium ions outside than inside.

Question 14

Which of the following is a real-world example of facilitated diffusion?

Accepted Answer

Glucose entering a muscle cell via a specific transporter protein.

Question 15

Which of the following is NOT a factor that influences membrane fluidity?

Accepted Answer

Cellular DNA content

Question 16

Which of the following best describes the role of glycoproteins in the plasma membrane?

Accepted Answer

They act as recognition keys for cell-to-cell communication.

Question 17

Which of the following transport mechanisms requires energy input from the cell?

Accepted Answer

Active transport

Question 18

A patient is given intravenous fluids that are isotonic to their blood plasma. What effect will this have on their red blood cells?

Accepted Answer

There will be no net movement of water, and the cells will remain unchanged.

Question 19

Which of the following best describes the movement of water across a semipermeable membrane?

Accepted Answer

Osmosis, which is the diffusion of water from an area of low solute concentration to high solute concentration.

Question 20

Which of the following is a correct statement about the phospholipid bilayer?

Accepted Answer

The hydrophobic tails face each other in the interior of the bilayer.

Cell Membrane Structure and Function: Study Notes

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