AQA GCSE BIOLOGY HIGHER TIER 1H
PRACTICE EXAM 2026 QUESTIONS WITH
VERIFIED SOLUTIONS
◉ how does the surface area of the cell membrane affect rate of
diffusion in and out of the cell? Answer: rate increases as the surface
area of the cell membrane increases
◉ give 2 examples of substances transported by diffusion in the
body Answer: -oxygen and carbon dioxide diffuse between blood
and the lungs (gas exchange)
-urea diffuses from cells into blood plasma
◉ what is osmosis? Answer: the diffusion of water molecules from a
dilute solution to a concentrated solution through a partially
permeable membrane.
◉ outline how the effect of different concentrations of salt solution
on plant tissue can be investigated? Answer: by comparing the
change in mass of potatoes cylinders after leaving them in different
concentrations of salt solutions for the same time.
(if a potato cylinder is left a salt solution with a higher concentration
of water than in potatoes cells, the cylinder draws in water by
osmosis and gets heavier)
,◉ give a brief method for investigating the effect of different
concentrations of salt solutions on plant tissue Answer: 1)cut
identical potatoes cylinders and record their mass
2)fill boiling tubes with a range of concentration of salt solution
e.g0-1 mol/dm^3
3)put cylinder in each tube
4)after 24 hours, remove and dry the cylinders, then record their
masses again.
◉ What is active transport? Answer: the movement of substances
from a more dilute solution to a more concentrated solution
◉ Why does active transport require energy? Answer: it moves
substances against a concentration gradient
◉ where does the energy required for active transport come from?
Answer: respiration.
◉ why do plant root hair cells use active transport to absorb mineral
ions from soil? Answer: the concentration of mineral ions in soil is
normally lower than the concentration of mineral ions in plant root
hair cells.
,this means that ions can't just diffuse in-so plant root hair cells use
active transport to absorb mineral ions from soil
◉ When is active transport used in the gut? Answer: When there is a
lower concentration of nutrients in the gut but a higher
concentration of nutrients in the blood
◉ how do u calculate surface area to volume ratio? Answer:
1)calculate the area of each surface and add them together
2)calculate volume
3)show as simplified ratio of total surface area to volume
◉ whats an exchange surface? Answer: a specialised area of an
organism that efficiently transfers substances between the organism
and its environment
◉ why don't single celled organisms need exchange surfaces ?
Answer: single celled organisms have relatively large surface area to
volume ratio.
this means substances can diffuse over their cell membranes at. rate
thats high enough to keep them alive.
this means single celled organisms don't need exchange surfaces
, ◉ why do multicellular organisms need exchange surfaces? Answer:
multicellular organisms have relatively small surface are to volume
ratio .
substances can't diffuse over their surfaces at a level thats high
enough to keep all of their cells alive.
this means that multi cellular organism need exchange surfaces to
transfer substances efficiently.
◉ give 4 adaptations of exchange surfaces to increase they
effectiveness Answer: -Large surface area(lets more substances
diffuse at once)
-Thin membrane (speeds up diffusion because diffusion distance is
short)
-Rich blood supply in animals.(takes things to and from exchange
surface efficiently )
-gas exchange surfaces are exposed to the air(in animals)
◉ give 3 ways that the small intestine is adapted for exchanging
surfaces Answer: -walls are folded and have millions of projections
called Villi to give a massive surface area
-Villi have very thin walls
PRACTICE EXAM 2026 QUESTIONS WITH
VERIFIED SOLUTIONS
◉ how does the surface area of the cell membrane affect rate of
diffusion in and out of the cell? Answer: rate increases as the surface
area of the cell membrane increases
◉ give 2 examples of substances transported by diffusion in the
body Answer: -oxygen and carbon dioxide diffuse between blood
and the lungs (gas exchange)
-urea diffuses from cells into blood plasma
◉ what is osmosis? Answer: the diffusion of water molecules from a
dilute solution to a concentrated solution through a partially
permeable membrane.
◉ outline how the effect of different concentrations of salt solution
on plant tissue can be investigated? Answer: by comparing the
change in mass of potatoes cylinders after leaving them in different
concentrations of salt solutions for the same time.
(if a potato cylinder is left a salt solution with a higher concentration
of water than in potatoes cells, the cylinder draws in water by
osmosis and gets heavier)
,◉ give a brief method for investigating the effect of different
concentrations of salt solutions on plant tissue Answer: 1)cut
identical potatoes cylinders and record their mass
2)fill boiling tubes with a range of concentration of salt solution
e.g0-1 mol/dm^3
3)put cylinder in each tube
4)after 24 hours, remove and dry the cylinders, then record their
masses again.
◉ What is active transport? Answer: the movement of substances
from a more dilute solution to a more concentrated solution
◉ Why does active transport require energy? Answer: it moves
substances against a concentration gradient
◉ where does the energy required for active transport come from?
Answer: respiration.
◉ why do plant root hair cells use active transport to absorb mineral
ions from soil? Answer: the concentration of mineral ions in soil is
normally lower than the concentration of mineral ions in plant root
hair cells.
,this means that ions can't just diffuse in-so plant root hair cells use
active transport to absorb mineral ions from soil
◉ When is active transport used in the gut? Answer: When there is a
lower concentration of nutrients in the gut but a higher
concentration of nutrients in the blood
◉ how do u calculate surface area to volume ratio? Answer:
1)calculate the area of each surface and add them together
2)calculate volume
3)show as simplified ratio of total surface area to volume
◉ whats an exchange surface? Answer: a specialised area of an
organism that efficiently transfers substances between the organism
and its environment
◉ why don't single celled organisms need exchange surfaces ?
Answer: single celled organisms have relatively large surface area to
volume ratio.
this means substances can diffuse over their cell membranes at. rate
thats high enough to keep them alive.
this means single celled organisms don't need exchange surfaces
, ◉ why do multicellular organisms need exchange surfaces? Answer:
multicellular organisms have relatively small surface are to volume
ratio .
substances can't diffuse over their surfaces at a level thats high
enough to keep all of their cells alive.
this means that multi cellular organism need exchange surfaces to
transfer substances efficiently.
◉ give 4 adaptations of exchange surfaces to increase they
effectiveness Answer: -Large surface area(lets more substances
diffuse at once)
-Thin membrane (speeds up diffusion because diffusion distance is
short)
-Rich blood supply in animals.(takes things to and from exchange
surface efficiently )
-gas exchange surfaces are exposed to the air(in animals)
◉ give 3 ways that the small intestine is adapted for exchanging
surfaces Answer: -walls are folded and have millions of projections
called Villi to give a massive surface area
-Villi have very thin walls
