Question 1

Which of the following best describes the structure of the cell membrane according to the fluid mosaic model?

Accepted Answer

A double layer of phospholipids with proteins, glycoproteins, and cholesterol drifting within it

Question 2

What is the primary reason phospholipids form bilayers in aqueous environments?

Accepted Answer

Their hydrophilic heads interact with water while hydrophobic tails avoid water

Question 3

Which of the following molecules can most easily diffuse directly through the cell membrane without assistance?

Accepted Answer

Oxygen ($O_2$)

Question 4

A patient receives an organ transplant but experiences organ rejection. Which cell membrane component is most directly involved in this immune response?

Accepted Answer

Glycoproteins

Question 5

Which of the following statements about cholesterol in cell membranes is TRUE?

Accepted Answer

Cholesterol helps maintain membrane fluidity across temperature changes in animal cells

Question 6

Which process requires energy in the form of ATP to move molecules against their concentration gradient?

Accepted Answer

Active transport

Question 7

A neuron maintains a high concentration of potassium ions ($K^+$) inside and sodium ions ($Na^+$) outside. Which membrane protein is responsible for this distribution?

Accepted Answer

Sodium-potassium pump

Question 8

Which of the following best explains why large polar molecules cannot easily cross the cell membrane?

Accepted Answer

The hydrophobic core of the membrane repels polar molecules

Question 9

During endocytosis, what happens to the plasma membrane?

Accepted Answer

It forms vesicles to bring substances into the cell

Question 10

Which of the following is a function of membrane proteins?

Accepted Answer

Facilitating cell-cell recognition, transport, and enzymatic activity

Question 11

If a cell is placed in a solution with a higher concentration of solutes than inside the cell, what will happen to the cell due to osmosis?

Accepted Answer

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

Question 12

Which equation best represents the movement of molecules during diffusion?

Accepted Answer

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

Question 13

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

Accepted Answer

Increasing the concentration gradient

Question 14

Which type of transport is used when glucose moves into a cell down its concentration gradient via a membrane protein?

Accepted Answer

Facilitated diffusion

Question 15

Which of the following statements about plant cell membranes is correct?

Accepted Answer

Plant cells adjust the proportion of saturated and unsaturated fatty acids to maintain membrane fluidity

Question 16

A cell uses ATP to move $Na^+$ ions from a region of low concentration inside the cell to a region of high concentration outside. Which type of transport is this?

Accepted Answer

Active transport

Question 17

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

Accepted Answer

They are involved in cell recognition and communication

Question 18

Which process is responsible for the movement of water across the cell membrane?

Accepted Answer

Osmosis

Question 19

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

Accepted Answer

Synthesizing DNA

Question 20

Which of the following best explains why the cell membrane is described as 'semipermeable'?

Accepted Answer

It allows some molecules to pass while restricting others

Cell Membrane Structure and Function: Study Notes for General Biology

Study Guide - Practice Questions

Study Guide - Flashcards