CAIE A-Level Biology 4.2 Movement Into and Out of Cells Question Bank

Practise membrane-transport questions by selecting diffusion, osmosis or active transport, interpreting water potential and calculating SA:V effects.

Exam points

select transport processes from gradient direction, membrane proteins, ATP use and vesicle movement
interpret osmosis and water potential data for plant cells, red blood cells and potato tissue
calculate SA:V ratios for agar blocks or cells and link diffusion distance to time taken

Covered syllabus points

4.2.1—Membrane transport processes 4.2.2—Diffusion and osmosis investigations 4.2.3—Surface area to volume ratios 4.2.4—SA:V ratio investigation 4.2.5—Water potential investigation 4.2.6—Water movement between cells

[Maximum number: 4]

(a)

Explain why sodium ions cannot cross phospholipid bilayers by simple diffusion.

[ 1 ]

(b)

Ions and some molecules move across cell surface membranes by facilitated diffusion and active transport.

Compare facilitated diffusion and active transport by stating one way in which they are similar and two ways in which facilitated diffusion is different from active transport.
similarity
difference 1
difference 2

[ 3 ]

[Maximum number: 1]

Four cylinders that were identical in size, A, B, C and D, were cut from potatoes that had been stored for different lengths of time.

The cylinders were weighed, immersed in 10\% salt solution for 45 minutes and then reweighed.
The percentage change in mass was then calculated.
Which cylinder had a water potential similar to the 10 % salt solution?

percentage

change in mass

-7.2

-2.5

-0.9

+3.4

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Covered syllabus points

4.2 Movement Into and Out of Cells question 1

Question (a)

Question (b)

4.2 Movement Into and Out of Cells question 2