Question 1

Which of the following statements is NOT part of modern cell theory?

Accepted Answer

Cells can spontaneously generate from non-living matter under certain conditions.

Question 2

A scientist observes a cell with a diameter of 100 μm. Based on the surface area-to-volume ratio, which of the following is most likely true about this cell compared to a typical human cell (10–15 μm diameter)?

Accepted Answer

It has a lower surface area-to-volume ratio, making diffusion less efficient.

Question 3

Which of the following best describes the Fluid Mosaic Model of the plasma membrane?

Accepted Answer

A flexible bilayer of phospholipids with proteins, carbohydrates, and cholesterol distributed throughout.

Question 4

Which component of the plasma membrane is primarily responsible for selective permeability?

Accepted Answer

Phospholipid bilayer

Question 5

A red blood cell is placed in a hypertonic solution. What will most likely happen to the cell, and why?

Accepted Answer

It will shrink because water moves out of the cell by osmosis.

Question 6

Which of the following transport mechanisms requires energy in the form of ATP?

Accepted Answer

Primary active transport

Question 7

A cell uses a sodium-glucose symporter to import glucose against its concentration gradient. Which type of transport is this, and what provides the energy?

Accepted Answer

Secondary active transport; sodium gradient established by ATP

Question 8

Which equation correctly represents the relationship between the rate of diffusion ($$J$$), surface area ($$A$$), concentration gradient ($$\Delta C$$), and membrane thickness ($$d$$)?

Accepted Answer

$$J = D \frac{A \Delta C}{d}$$

Question 9

Which of the following best explains why small, nonpolar molecules can cross the plasma membrane more easily than large, polar molecules?

Accepted Answer

The hydrophobic core of the phospholipid bilayer allows nonpolar molecules to diffuse through.

Question 10

A patient is given a large volume of pure water intravenously. What is the most likely consequence at the cellular level?

Accepted Answer

Cells will swell and may burst due to water influx.

Question 11

Which of the following is an example of receptor-mediated endocytosis?

Accepted Answer

Uptake of low-density lipoprotein (LDL) particles by liver cells

Question 12

Which of the following best describes the function of the sodium-potassium pump ($$\mathrm{Na^+/K^+}-$$ATPase) in animal cells?

Accepted Answer

It uses ATP to move sodium out of the cell and potassium into the cell, both against their gradients.

Question 13

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

Accepted Answer

Storing genetic information

Question 14

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 15

Which of the following best describes the process of exocytosis?

Accepted Answer

Release of large molecules from the cell by fusion of vesicles with the plasma membrane

Question 16

Which of the following factors would NOT increase the rate of diffusion across a cell membrane?

Accepted Answer

Decreasing the concentration gradient

Question 17

Which of the following best explains why the resting membrane potential of a typical animal cell is negative?

Accepted Answer

There are more negative charges lining the inside of the plasma membrane.

Question 18

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

Accepted Answer

Glucose symport with sodium using the sodium gradient

Question 19

A cell engulfs a bacterium by surrounding it with its plasma membrane and forming a vesicle. What is this process called?

Accepted Answer

Phagocytosis

Question 20

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

Accepted Answer

It stabilizes membrane fluidity and structure.

Chapter three pt. 1

Guida di studio - Domande di pratica

Study guide - Flashcard