Question 1

Which of the following best describes the fluid mosaic model of the plasma membrane?

Accepted Answer

A dynamic bilayer of phospholipids with proteins and carbohydrates embedded or attached, allowing for flexibility and selective permeability.

Question 2

A red blood cell is placed in a solution and begins to shrink. Which of the following best describes the solution and the process occurring?

Accepted Answer

The solution is hypertonic, and the cell is undergoing crenation due to osmosis.

Question 3

Which of the following is a function of integral membrane proteins?

Accepted Answer

Acting as transport channels, receptors, and enzymes within the membrane.

Question 4

Which cell junction would be most important in tissues that experience significant mechanical stress, such as cardiac muscle?

Accepted Answer

Desmosomes

Question 5

A solution contains 1 M NaCl. What is its osmolarity?

Accepted Answer

$$2 \, 	ext{osmol/L}$$

Question 6

Which of the following best explains why water moves into a cell placed in a hypotonic solution?

Accepted Answer

Water moves from an area of high water concentration (outside the cell) to low water concentration (inside the cell) by osmosis.

Question 7

Which of the following molecules would most easily diffuse through the plasma membrane by simple diffusion?

Accepted Answer

Oxygen ($$O_2)$$

Question 8

A patient receives an intravenous solution that is isotonic to their blood plasma. What effect will this have on their red blood cells?

Accepted Answer

Cells will retain their normal shape and volume.

Question 9

Which of the following best describes the role of the glycocalyx?

Accepted Answer

It serves as a biological marker for cell recognition and immune response.

Question 10

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It uses carrier or channel proteins to move substances down their concentration gradient without energy input.

Question 11

A cell is placed in a solution and water moves into the cell, causing it to swell. Which term best describes the solution?

Accepted Answer

Hypotonic

Question 12

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

Accepted Answer

Forming channels for facilitated diffusion

Question 13

Which of the following best explains why burn patients are at risk for dehydration?

Accepted Answer

Damaged plasma membranes allow free diffusion of fluids and ions, disrupting concentration gradients.

Question 14

Which of the following cell junctions allows for the rapid passage of ions and electrical signals between cardiac muscle cells?

Accepted Answer

Gap junctions

Question 15

Which of the following factors would increase the rate of diffusion across a plasma membrane?

Accepted Answer

Increasing the concentration gradient

Question 16

Which of the following best describes osmosis?

Accepted Answer

Movement of water from low solute concentration to high solute concentration through a selectively permeable membrane.

Question 17

A cell with a defective glycocalyx is most likely to experience which of the following problems?

Accepted Answer

Difficulty in cell-to-cell recognition and immune response

Question 18

Which of the following is true regarding the relationship between osmolarity and water movement?

Accepted Answer

Water moves from areas of low osmolarity to high osmolarity.

Question 19

Which of the following best explains why plant cells do not burst when placed in a hypotonic solution, but animal cells do?

Accepted Answer

Plant cells have a rigid cell wall that limits hydrostatic pressure.

Question 20

Which of the following is a correct statement about the structure of phospholipids in the plasma membrane?

Accepted Answer

The hydrophilic heads face the aqueous environments inside and outside the cell, while the hydrophobic tails face each other.

Cells: The Living Units – Structure and Function of the Plasma Membrane

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