AQA AS BIOLOGY 7401/2 PAPER 2 MARK
SCHEME FINAL TEST 2026 QUESTIONS
WITH CORRECT ANSWERS GRADED A+
◍ Draw a labelled diagram to show the structure of a motor neuron. [4 marks].
Answer: Award [1] for each structure clearly drawn and labelled.a. cell body
- star shaped body at end of neuron with nucleus inside;b. dendrites - as
multiple long/narrow protrusions from the cell body;c. axon - at least three
times as long as the cell body not including the dendrites;d. myelin
sheath/Schwann cells - surrounding the axon;e. nodes of Ranvier - periodic
gaps in myelin sheath;f. motor end plates - shown as buttons at the end of
multiple branches of axon;Reject the points for axon and myelin sheath if
the labelling line does not clearly point to the structure. Accept a bracket
label indicating the length of the axon.
◍ Distinguish between the absorption of red light, blue light and green light by
plants. [4 marks].
Answer: a. chlorophyll is the main photosynthetic pigment;b. high levels of
absorption in red light and blue light; (both needed) c. greatest absorption in
blue light;d. least/lowabsorptioningreenlight;e. green light is reflected;f.
other pigments absorb other wavelengths/colours;
◍ Explain the presence of glucose in the urine of a diabetic person and its
absence in the urine of a person with type I diabetes that is being
successfully treated. [8 marks].
Answer: a. glucose filtered out of blood (plasma) in glomerulus;b. glucose
reabsorbed from filtrate in proximal convoluted tubule;c. by active
transport;d. reference to specific pumps for glucose / limited capacity for
glucose uptake;e. in diabetic patients glucose concentration in plasma is
high;f. not all glucose can be reabsorbed (in PCT) /capacity for reabsorption
, exceeded; g. no glucose reabsorption after the proximal convoluted tubule;h.
glucose still present at end of nephron/collecting duct/in the ureter/bladder;i.
type I diabetes treated with insulin;j. insulin reduces the glucose
concentration of blood/plasma/filtrate;k. all glucose reabsorbed from filtrate
in Type I diabetics if treated;Do not award a mark simply for stating that
glucose is present in the urine as this is in the question.Reject regulates
glucose concentration.
◍ Outline the effects of a base substitution mutation in the case of sickle-cell
anemia. [5 marks].
Answer: a. DNA changes from GAG to GTG/CTC to CAC b. mRNA
changes from GAG to GUG; c. affecting the process of translation/causes
different primary structure of polypeptide;d. causing glutamic acid to be
replaced by valine;changing the form of hemoglobin;e. changes the shape of
the red blood cells / red blood cells become sickle shaped; f. transport
oxygen less efficiently/less oxygen gets to tissues;g. sickled cells block
capillaries;h. muscular pain/severe anemia/slow growth; i. (allow other
appropriate symptom) correlated with protection against malaria in
heterozygotes;
◍ Paper 2 - Knowledge-Based Essays.
Answer: 60 Marks totalSelect TWO of the three topics (Unit 1, Unit 2, or
Unit 3) and answer Part (a) AND Part (b) for both. Ignore the third topic
entirely. This means you will have FOUR essays total to write.Each Part (a)
- 10 marks - Causation, Explain Why? - 20 minEach Part (b) - 20 marks -
How far do the sources support the claim in the question? - 35 min
◍ Explain how abiotic factors affect the rate of transpiration in terrestrial
plants. [8 marks].
Answer: a. less transpiration/water loss as (atmospheric) humidity rises;b.
air spaces inside leaf are saturated/nearly saturated (with water vapour);c.
smaller concentration gradient with higher atmospheric humidity;d. more
transpiration/water loss as temperature rises/with more heat;e. faster
diffusion / more kinetic energy (of water molecules);f. faster evaporation
, (due to more latent heat available);g. more transpiration/water loss as wind
(speed) increases;h. humid air/water vapour blown away from the leaf;i.
increasing the concentration gradient (of water vapour);j. more
transpiration/water loss in the light;k. light causes stomata to open / stomata
closed in darkness;l. low CO2 concentration inside leaf in bright light so
stomata open wider;Accept any of the points if clearly made on an annotated
graph.
◍ Explain how skeletal muscle contracts. [8 marks].
Answer: a. sliding filament model / filaments/actin and myosin slide past
each other;b. action potential/depolarisation/nerve impulse arrives at end of
motor neurone;c. neurotransmitter/acetylcholine released causing action
potential (in muscle sliding filament model / filaments/actin and myosin
slide past each other; fibre);d. sarcoplasmic reticulum releases calcium
ions;e. calcium ions cause binding sites on actin/for myosin to be exposed;f.
myosin heads bind to sites on actin/form cross-bridges;g. myosin (head)
moves actin filament using energy from ATP;h. actin moved towards the
centre of sarcomere/M line/M band;i. sarcomeres shortened;j. (binding of)
ATP causes release of myosin head from actin;k. conversion of ATP to ADP
and Pi causes myosin heads to change angle;l. cycle (of events) repeated
(during muscle contraction);Accept the above points in annotated diagrams.
◍ Describe the process of endocytosis. [5 marks].
Answer: a. (plasma) membrane encloses/engulfs solid particles/droplets of
fluid/molecules;b. fluidity of the membrane allows endocytosis;c. plasma
membrane forms pit/forms indentation/pulled inwards/invaginates;d.
membrane pinches off/seals back on itself/edges fuse;e. vesicle/vacuole
formed;f. inside of plasma membrane becomes outside of vesicle membrane
/ converse;g. vesicle breaks away from plasma membrane/moves into
cytoplasm;h. active process / endocytosis/vesicle formation requires
energy;(plasma) membrane encloses/engulfs solid particles/droplets of
fluid/molecules;Accept any of the above points clearly described in an
annotated diagram.
SCHEME FINAL TEST 2026 QUESTIONS
WITH CORRECT ANSWERS GRADED A+
◍ Draw a labelled diagram to show the structure of a motor neuron. [4 marks].
Answer: Award [1] for each structure clearly drawn and labelled.a. cell body
- star shaped body at end of neuron with nucleus inside;b. dendrites - as
multiple long/narrow protrusions from the cell body;c. axon - at least three
times as long as the cell body not including the dendrites;d. myelin
sheath/Schwann cells - surrounding the axon;e. nodes of Ranvier - periodic
gaps in myelin sheath;f. motor end plates - shown as buttons at the end of
multiple branches of axon;Reject the points for axon and myelin sheath if
the labelling line does not clearly point to the structure. Accept a bracket
label indicating the length of the axon.
◍ Distinguish between the absorption of red light, blue light and green light by
plants. [4 marks].
Answer: a. chlorophyll is the main photosynthetic pigment;b. high levels of
absorption in red light and blue light; (both needed) c. greatest absorption in
blue light;d. least/lowabsorptioningreenlight;e. green light is reflected;f.
other pigments absorb other wavelengths/colours;
◍ Explain the presence of glucose in the urine of a diabetic person and its
absence in the urine of a person with type I diabetes that is being
successfully treated. [8 marks].
Answer: a. glucose filtered out of blood (plasma) in glomerulus;b. glucose
reabsorbed from filtrate in proximal convoluted tubule;c. by active
transport;d. reference to specific pumps for glucose / limited capacity for
glucose uptake;e. in diabetic patients glucose concentration in plasma is
high;f. not all glucose can be reabsorbed (in PCT) /capacity for reabsorption
, exceeded; g. no glucose reabsorption after the proximal convoluted tubule;h.
glucose still present at end of nephron/collecting duct/in the ureter/bladder;i.
type I diabetes treated with insulin;j. insulin reduces the glucose
concentration of blood/plasma/filtrate;k. all glucose reabsorbed from filtrate
in Type I diabetics if treated;Do not award a mark simply for stating that
glucose is present in the urine as this is in the question.Reject regulates
glucose concentration.
◍ Outline the effects of a base substitution mutation in the case of sickle-cell
anemia. [5 marks].
Answer: a. DNA changes from GAG to GTG/CTC to CAC b. mRNA
changes from GAG to GUG; c. affecting the process of translation/causes
different primary structure of polypeptide;d. causing glutamic acid to be
replaced by valine;changing the form of hemoglobin;e. changes the shape of
the red blood cells / red blood cells become sickle shaped; f. transport
oxygen less efficiently/less oxygen gets to tissues;g. sickled cells block
capillaries;h. muscular pain/severe anemia/slow growth; i. (allow other
appropriate symptom) correlated with protection against malaria in
heterozygotes;
◍ Paper 2 - Knowledge-Based Essays.
Answer: 60 Marks totalSelect TWO of the three topics (Unit 1, Unit 2, or
Unit 3) and answer Part (a) AND Part (b) for both. Ignore the third topic
entirely. This means you will have FOUR essays total to write.Each Part (a)
- 10 marks - Causation, Explain Why? - 20 minEach Part (b) - 20 marks -
How far do the sources support the claim in the question? - 35 min
◍ Explain how abiotic factors affect the rate of transpiration in terrestrial
plants. [8 marks].
Answer: a. less transpiration/water loss as (atmospheric) humidity rises;b.
air spaces inside leaf are saturated/nearly saturated (with water vapour);c.
smaller concentration gradient with higher atmospheric humidity;d. more
transpiration/water loss as temperature rises/with more heat;e. faster
diffusion / more kinetic energy (of water molecules);f. faster evaporation
, (due to more latent heat available);g. more transpiration/water loss as wind
(speed) increases;h. humid air/water vapour blown away from the leaf;i.
increasing the concentration gradient (of water vapour);j. more
transpiration/water loss in the light;k. light causes stomata to open / stomata
closed in darkness;l. low CO2 concentration inside leaf in bright light so
stomata open wider;Accept any of the points if clearly made on an annotated
graph.
◍ Explain how skeletal muscle contracts. [8 marks].
Answer: a. sliding filament model / filaments/actin and myosin slide past
each other;b. action potential/depolarisation/nerve impulse arrives at end of
motor neurone;c. neurotransmitter/acetylcholine released causing action
potential (in muscle sliding filament model / filaments/actin and myosin
slide past each other; fibre);d. sarcoplasmic reticulum releases calcium
ions;e. calcium ions cause binding sites on actin/for myosin to be exposed;f.
myosin heads bind to sites on actin/form cross-bridges;g. myosin (head)
moves actin filament using energy from ATP;h. actin moved towards the
centre of sarcomere/M line/M band;i. sarcomeres shortened;j. (binding of)
ATP causes release of myosin head from actin;k. conversion of ATP to ADP
and Pi causes myosin heads to change angle;l. cycle (of events) repeated
(during muscle contraction);Accept the above points in annotated diagrams.
◍ Describe the process of endocytosis. [5 marks].
Answer: a. (plasma) membrane encloses/engulfs solid particles/droplets of
fluid/molecules;b. fluidity of the membrane allows endocytosis;c. plasma
membrane forms pit/forms indentation/pulled inwards/invaginates;d.
membrane pinches off/seals back on itself/edges fuse;e. vesicle/vacuole
formed;f. inside of plasma membrane becomes outside of vesicle membrane
/ converse;g. vesicle breaks away from plasma membrane/moves into
cytoplasm;h. active process / endocytosis/vesicle formation requires
energy;(plasma) membrane encloses/engulfs solid particles/droplets of
fluid/molecules;Accept any of the above points clearly described in an
annotated diagram.
