AQA GCSE Biology (8461), Higher tier · Cell biology › Transport in cells
Practise Active transport. 11 exam-style questions plus unlimited generated ones on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
Some substances enter cells by active transport.
(a) What is meant by active transport?[2]
(b) Which process needs energy from respiration? Tick (✓) one box.[1]
Active transport
Diffusion
Osmosis
Evaporation
(c) Name one type of substance that plant root hair cells absorb from the soil by active transport.[1]
Show the answer and mark scheme
(a)
movement of substances from a more dilute solution to a more concentrated solution / against a concentration gradient
using energy from respiration
(b)Answer: Active transport
(c)
mineral ions
Question 2Medium6 marks
Substances move into and out of cells by diffusion, osmosis and active transport.
(a) Give two differences between active transport and diffusion.[2]
(b) Give one similarity between osmosis and active transport.[1]
(c) After a meal, sugar molecules are absorbed from the small intestine into the blood. Explain why active transport is needed to absorb all of the sugar.[2]
(d) Give one use of the sugar absorbed into the blood.[1]
Show the answer and mark scheme
(a)
active transport needs energy from respiration, but diffusion does not
active transport moves substances from a dilute to a more concentrated solution / against the concentration gradient, but diffusion moves substances from a higher to a lower concentration
(b)
both move substances across (partially permeable) cell membranes
(c)
(as sugar is absorbed) the sugar concentration in the gut becomes lower than in the blood
so sugar cannot be absorbed by diffusion / must be moved against the concentration gradient
(d)
(cell) respiration
Question 3Hard6 marks
Substances move into and out of cells by diffusion, osmosis and active transport.
Describe how substances are transported into and out of cells by diffusion, osmosis and active transport. Explain the differences between the three processes. Use examples in your answer.[6]
Show the answer and mark scheme
diffusion is the net movement of particles from a higher to a lower concentration (down a concentration gradient)
e.g. oxygen diffuses into cells / carbon dioxide diffuses out of cells / urea diffuses from cells into the blood plasma
osmosis is the diffusion of water from a dilute solution to a more concentrated solution through a partially permeable membrane
e.g. water enters root hair cells by osmosis
active transport moves substances from a more dilute solution to a more concentrated solution (against a concentration gradient)
active transport needs energy from respiration; diffusion and osmosis do not
e.g. mineral ions are absorbed into root hair cells / sugar is absorbed from the gut into the blood by active transport
osmosis involves only water; diffusion and active transport move dissolved substances / gases
Marked with levels of response: the full level descriptors are in the app.