AQA AS BIOLOGY 7401/2 PAPER 2 MARK
SCHEME COMPREHENSIVE STUDY GUIDE
2026 FULL QUESTIONS AND SOLUTIONS
GRADED A+
◍ Describe how meiosis produces cells that are genetically different.
Answer: random chromosome from each pair (of chromosomes) moves to
one end of the cell (new cell)
◍ Name the type of response by the seedling in experiment A.
Answer: phototropism
◍ Explain why a person with MSUD must have a low-protein diet.
Answer: -proteins contain amino acids-must keep (certain) amino acids in
low amount-so toxic substance does not build up in the body
◍ A student repeated the scientist's method.The student used a thin coverslip
over the diluted pond water instead of the thick coverslip.The liquid pulled
the thin coverslip downwards slightlyExplain how the use of the thin
coverslip would affect the results for the cell count.
Answer: Smaller volume so fewer cells
◍ Suggest why the athlete was advised to take salt tablets every day.
Answer: to replace ions lost in sweat.
◍ Describe what happens to glucose, protein and urea in the kidneys..
Answer: Glucose an urea is diluted out of the blood. Protein is not filtered.
All glucose is reabsorbed. Urea is passed out by urine
◍ Suggest why the scientist diluted the pond water before placing it on the
special slide.
Answer: to make it easier to count
, ◍ Suggest two ways to improve the students' method for measuringhuman
reaction time..
Answer: Repeat/calculate mean and use the same starting position
◍ Explain how having yellow and black markings helps the hoverfly survive..
Answer: Hoverfly looks like a wasp. Predators avoid them so it does not get
stung so the predator does not attack (3)
◍ Genetically identical tomato plants growing in the same garden do not all
grow to thesame height.Give one reason why..
Answer: Light
◍ Students investigated the response of plant shoots to one-sided light.Suggest
two control variables the students should have used in their investigation..
Answer: same volume of watersame type of plant
◍ During hibernation the echidna wakes up several timesEach time the
echidna wakes up it becomes active and its body temperature increases over
30 degreesExplain why the echidna has a higher body temperature when it is
active..
Answer: -movement requires energy from respiration-and respiration
releases heat which increases body temperature
◍ Give two ways that coordination by the endocrine system is different
fromcoordination by the nervous system..
Answer: Longer lasting and hormones are transporting by the blood
◍ Name three harmful substances that could cause water pollutionDo not refer
to plastic or to litter in your answer.
Answer: FertiliserSewageherbicide
◍ The athlete's energy intake each day from food was 20 000 kJ.Evaporation
of 1cm^3 sweat requires 2.5 kJ of energy.40% of the athlete's daily energy
intake was used to evaporate sweat.Calculate the volume of sweat the
athlete lost each day.Give your answers in dm^31dm^3 = 1000 cm^3.
Answer: 20 000 x x 2.5 = 3200 cm^ = 3.2
SCHEME COMPREHENSIVE STUDY GUIDE
2026 FULL QUESTIONS AND SOLUTIONS
GRADED A+
◍ Describe how meiosis produces cells that are genetically different.
Answer: random chromosome from each pair (of chromosomes) moves to
one end of the cell (new cell)
◍ Name the type of response by the seedling in experiment A.
Answer: phototropism
◍ Explain why a person with MSUD must have a low-protein diet.
Answer: -proteins contain amino acids-must keep (certain) amino acids in
low amount-so toxic substance does not build up in the body
◍ A student repeated the scientist's method.The student used a thin coverslip
over the diluted pond water instead of the thick coverslip.The liquid pulled
the thin coverslip downwards slightlyExplain how the use of the thin
coverslip would affect the results for the cell count.
Answer: Smaller volume so fewer cells
◍ Suggest why the athlete was advised to take salt tablets every day.
Answer: to replace ions lost in sweat.
◍ Describe what happens to glucose, protein and urea in the kidneys..
Answer: Glucose an urea is diluted out of the blood. Protein is not filtered.
All glucose is reabsorbed. Urea is passed out by urine
◍ Suggest why the scientist diluted the pond water before placing it on the
special slide.
Answer: to make it easier to count
, ◍ Suggest two ways to improve the students' method for measuringhuman
reaction time..
Answer: Repeat/calculate mean and use the same starting position
◍ Explain how having yellow and black markings helps the hoverfly survive..
Answer: Hoverfly looks like a wasp. Predators avoid them so it does not get
stung so the predator does not attack (3)
◍ Genetically identical tomato plants growing in the same garden do not all
grow to thesame height.Give one reason why..
Answer: Light
◍ Students investigated the response of plant shoots to one-sided light.Suggest
two control variables the students should have used in their investigation..
Answer: same volume of watersame type of plant
◍ During hibernation the echidna wakes up several timesEach time the
echidna wakes up it becomes active and its body temperature increases over
30 degreesExplain why the echidna has a higher body temperature when it is
active..
Answer: -movement requires energy from respiration-and respiration
releases heat which increases body temperature
◍ Give two ways that coordination by the endocrine system is different
fromcoordination by the nervous system..
Answer: Longer lasting and hormones are transporting by the blood
◍ Name three harmful substances that could cause water pollutionDo not refer
to plastic or to litter in your answer.
Answer: FertiliserSewageherbicide
◍ The athlete's energy intake each day from food was 20 000 kJ.Evaporation
of 1cm^3 sweat requires 2.5 kJ of energy.40% of the athlete's daily energy
intake was used to evaporate sweat.Calculate the volume of sweat the
athlete lost each day.Give your answers in dm^31dm^3 = 1000 cm^3.
Answer: 20 000 x x 2.5 = 3200 cm^ = 3.2
