Question 1

Which scientist's experiment provided crucial evidence that all cells come from preexisting cells, supporting the third tenet of cell theory?

Accepted Answer

Louis Pasteur

Question 2

According to the fluid mosaic model, which statement best describes the distribution of proteins in the cell membrane?

Accepted Answer

Proteins are interspersed within the lipid bilayer, allowing for dynamic movement and function.

Question 3

A nerve cell is much longer than a skin cell. Which concept explains why most human cells are limited in size despite such variation in morphology?

Accepted Answer

Cells must maintain a high surface area to volume ratio for efficient exchange of materials.

Question 4

Which of the following is NOT a component of the plasma membrane?

Accepted Answer

Cytosol

Question 5

What is the primary function of the glycocalyx on the cell membrane?

Accepted Answer

To serve as a unique identifier for the cell and guide cell interactions

Question 6

Which of the following best describes simple diffusion across a cell membrane?

Accepted Answer

Movement of solutes down their concentration gradient without energy input

Question 7

A patient is severely dehydrated after strenuous exercise. Which solution would most safely restore normal cytosol concentration in their cells?

Accepted Answer

A hypotonic sports drink containing water, electrolytes, and carbohydrates

Question 8

Which equation best represents the relationship between diffusion rate ($R$) and membrane surface area ($A$), assuming other factors are constant?

Accepted Answer

$R = k 	imes A$

Question 9

Which of the following is an example of primary active transport?

Accepted Answer

Sodium-potassium pump

Question 10

During secondary active transport, what provides the energy for the movement of molecules against their concentration gradient?

Accepted Answer

Concentration gradient of a co-transported molecule

Question 11

Which process allows a cell to engulf large particles such as bacteria?

Accepted Answer

Phagocytosis

Question 12

What is the main consequence of ion transport across the plasma membrane in terms of cell physiology?

Accepted Answer

It produces an electrical gradient, resulting in membrane potential.

Question 13

Which of the following statements about membrane proteins is TRUE?

Accepted Answer

Integral proteins span the membrane and can act as channels.

Question 14

A cell is placed in a solution with a lower solute concentration than its cytosol. What will happen to the cell?

Accepted Answer

Water will move into the cell, potentially causing it to swell.

Question 15

Which formula best describes the effect of molecular mass ($M$) on the rate of diffusion ($R$) across a membrane?

Accepted Answer

$R \propto \frac{1}{M}$

Question 16

Which of the following is a function of membrane carbohydrates?

Accepted Answer

Acting as unique identifiers for cell recognition

Question 17

Which process is responsible for the secretion of large molecules, such as hormones, from a cell?

Accepted Answer

Exocytosis

Question 18

A cell uses a receptor-mediated process to take up LDL cholesterol from the bloodstream. Which type of transport is this?

Accepted Answer

Receptor-mediated endocytosis

Question 19

Which of the following best explains why aquaporins are important in cell membranes?

Accepted Answer

They allow water to diffuse rapidly across the membrane, regulating osmotic rate.

Question 20

Which of the following is NOT a statement of the modern cell theory?

Accepted Answer

Cells can arise spontaneously from non-living matter.

The Cell Membrane: Structure, Function, and Transport Mechanisms (Chapter 3: 3.1–3.3)

Study Guide - Practice Questions