Question 1

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

Accepted Answer

A flexible bilayer of phospholipids with embedded proteins that move and shift, creating a dynamic pattern.

Question 2

Which component of the plasma membrane is primarily responsible for increasing membrane stability?

Accepted Answer

Cholesterol

Question 3

A patient receives an intravenous solution that is hypertonic relative to their red blood cells. What is the most likely effect on the cells?

Accepted Answer

The cells will shrink (crenate) as water leaves the cells.

Question 4

Which of the following best explains why oxygen and carbon dioxide can easily cross the plasma membrane?

Accepted Answer

They are nonpolar and lipid-soluble, allowing them to diffuse directly through the lipid bilayer.

Question 5

Which type of membrane protein is most likely to function as a receptor for signal transduction?

Accepted Answer

Integral protein

Question 6

A cell is placed in a solution and begins to swell until it bursts. Which of the following best describes the solution?

Accepted Answer

Hypotonic

Question 7

Which of the following equations correctly relates osmolarity ($$Osm) to $$molarity ($$M) $$for a salt that dissociates into $$n$$ particles?

Accepted Answer

$$Osm = M 	imes n$$

Question 8

Which of the following is a function of the glycocalyx on the cell surface?

Accepted Answer

Serves as a biological marker for cell-to-cell recognition.

Question 9

Which type of cell junction would be most important in preventing leakage of digestive enzymes between cells lining the stomach?

Accepted Answer

Tight junctions

Question 10

A scientist observes that a certain membrane protein is involved in catalyzing sequential steps of a metabolic pathway. This protein is most likely functioning as:

Accepted Answer

An enzyme

Question 11

Which of the following best describes the movement of water during osmosis?

Accepted Answer

Water moves from areas of low solute concentration (high water concentration) to high solute concentration (low water concentration).

Question 12

Which of the following is true regarding carrier-mediated facilitated diffusion?

Accepted Answer

It involves transmembrane proteins that change shape to transport specific molecules down their concentration gradient.

Question 13

A burn patient is losing large amounts of fluids and proteins from damaged cells. Which property of the plasma membrane has been compromised?

Accepted Answer

Selective permeability

Question 14

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

Accepted Answer

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

Question 15

Which of the following is a correct statement about desmosomes?

Accepted Answer

They provide anchoring strength and allow 'give' between cells, reducing tearing under tension.

Question 16

Which of the following best describes the function of gap junctions in cardiac muscle?

Accepted Answer

They allow electrical signals to pass quickly from one cell to the next.

Question 17

If a cell is placed in a 1 M NaCl solution, what is the osmolarity of the solution?

Accepted Answer

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

Question 18

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

Accepted Answer

Transport of substances across the membrane as channels

Question 19

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

Accepted Answer

Increasing the concentration gradient

Question 20

A mutation causes the glycocalyx of a cell to change rapidly, making it unrecognizable to the immune system. What is a likely consequence?

Accepted Answer

The cell may evade immune detection and continue to replicate, as seen in some cancer cells.

Chapter 03A

Guida di studio - Domande di pratica

Study guide - Flashcard