Question 1

Which of the following best describes passive transport across a biological membrane?

Accepted Answer

Movement of substances down their concentration gradient without energy expenditure

Question 2

A red blood cell is placed in a hypotonic solution. What is the most likely outcome?

Accepted Answer

The cell will gain water and swell, possibly lysing

Question 3

Which equation best represents the relationship between the rate of diffusion ($$R) $$and the concentration gradient ($$\Delta C$$)?

Accepted Answer

$$R = k 	imes \Delta C$$

Question 4

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

It uses transport proteins to move substances down their concentration gradient

Question 5

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

Accepted Answer

Sodium-potassium pump transporting $$Na^+$$ and $$K^+$$ ions using ATP

Question 6

A cell is placed in an isotonic solution. What will happen to the net movement of water?

Accepted Answer

There will be no net movement of water

Question 7

Which of the following statements about membrane potential is correct?

Accepted Answer

It is generated by active transport of ions such as $$Na^+$$ and $$K^+$$

Question 8

Which type of transport protein is responsible for moving water molecules across the membrane?

Accepted Answer

Aquaporin

Question 9

In the sodium-potassium pump, how many $$Na^+$$ ions are moved out of the cell for every cycle?

Accepted Answer

3

Question 10

Which of the following best explains why facilitated diffusion is considered passive transport?

Accepted Answer

It moves molecules down their concentration gradient without energy input

Question 11

A plant cell in a hypertonic solution will:

Accepted Answer

Lose water and become flaccid

Question 12

Which of the following is NOT a factor that affects the rate of diffusion across a membrane?

Accepted Answer

ATP concentration in the cell

Question 13

Which equation represents the energy required ($$E) $$for active transport against a concentration gradient ($$\Delta G$$)?

Accepted Answer

$$E = \Delta G$$

Question 14

Which of the following transport mechanisms is used by cells to import glucose together with sodium ions?

Accepted Answer

Symporter

Question 15

What is the main electrogenic pump in animal cells?

Accepted Answer

Sodium-potassium pump

Question 16

Which of the following best describes the process of osmosis?

Accepted Answer

Movement of water molecules across a selectively permeable membrane from low to high solute concentration

Question 17

A cell uses a proton pump to create a gradient. Which type of transport uses this gradient to move sucrose into the cell?

Accepted Answer

Coupled transport (cotransport)

Question 18

Which of the following is true about carrier proteins in facilitated diffusion?

Accepted Answer

They change shape when binding to the transported molecule

Question 19

Which of the following is a common misconception about active transport?

Accepted Answer

It does not require any energy input

Question 20

If a cell membrane is more permeable to potassium ions than sodium ions, what effect does this have on membrane potential?

Accepted Answer

The inside of the cell becomes more negative

Passive, Facilitated, and Active Transport Across Membranes

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