GCSE Combined Science Transport in cells questions by topic

This question is about diffusion.

1. (a)Define diffusion.[2]
2. (b)Name one gas that diffuses into the blood at the lungs and one that diffuses out.[2]

This question is about the ways substances cross cell membranes.

1. (a)Name the process by which water moves through a partially permeable membrane.[1]
2. (b)Name the process that moves substances against the concentration gradient.[1]
3. (c)State which organelle supplies the energy for (b).[1]
4. (d)State one substance that leaves a cell by diffusion.[1]

A student places plant tissue into pure water and into a strong salt solution.

1. (a)State and explain what happens to the tissue in pure water.[2]
2. (b)State and explain what happens to the tissue in the strong salt solution.[2]

This question is about the osmosis required practical.

1. (a)State the independent variable.[1]
2. (b)State the dependent variable.[1]
3. (c)Give one variable that must be controlled and say how.[2]

A cube-shaped cell has sides of 3 mm.

1. (a)Calculate the surface area of the cell.[2]
2. (b)Calculate the volume of the cell.[1]
3. (c)Give the surface-area-to-volume ratio in its simplest form.[1]

A chip of plant tissue starts at 6.4 g. After 30 minutes in dilute solution it weighs 7.2 g.

1. (a)Calculate the change in mass in grams.[1]
2. (b)Calculate the percentage change in mass.[2]
3. (c)State what the result shows about the direction of water movement.[1]

A second chip starts at 8.0 g and finishes at 7.6 g in a concentrated solution.

1. (a)Calculate its percentage change in mass.[2]
2. (b)Explain why the percentage change is negative.[1]

A class plots percentage change in mass against sugar concentration and draws a straight line from +14% at 0 mol/dm³ to −10% at 1.0 mol/dm³.

1. (a)Use the graph to estimate the concentration at which the change is zero. Show your working.[2]
2. (b)State what this concentration represents.[1]
3. (c)State one reason why the estimate is uncertain.[1]

Compare active transport and diffusion in root hair cells.

1. (a)Describe the direction of movement in each process.[2]
2. (b)Explain why each process is used for a different substance in root hair cells.[2]
3. (c)Name the organelle that makes active transport possible here.[1]

A student cuts chips with a knife instead of a cork borer and leaves some tubes for 20 minutes and others for 40 minutes.

1. (a)Explain two ways each mistake could make the results unreliable.[4]
2. (b)State one improvement for each mistake.[1]

Explain why a single-celled organism does not need a transport system but a human does.

1. (a)Compare the surface-area-to-volume ratio of a single cell and a human.[2]
2. (b)Explain the consequence of this difference for supplying cells with oxygen.[3]
3. (c)Name the human organ system that solves the problem.[1]

A garden irrigation fault floods a flowerbed with seawater for a day.

1. (a)Explain what happens to the root cells of the plants.[3]
2. (b)Explain why the plants wilt even though the soil is soaking wet.[2]