AQA A LEVEL BIOLOGY PAPER 2
7402-2 MARK SCHEME MS PRACTICE
EXAMINATION 2026 QUESTIONS
WITH ANSWERS GRADED A+
◍ Draw a labelled diagram of the human adult male reproductive system. [5
marks].
Answer: a. scrotum - shown around testes;b. testes/testis/testicles - shown
inside scrotum;c. epididymis - shown adjacent to testis and connected to
sperm duct;d. sperm duct/vas deferens - double line connecting
testis/epididymis to urethra; e. seminal vesicle - sac shown branched off
sperm duct (not off the urethra);f. prostate gland - shown positioned where
sperm duct connects with urethra; g. urethra - shown as double line linking
bladder to end of penis;h. penis - with urethra passing through it;Award [1]
for each structure clearly drawn and labelled that conforms to the italicized
guidelines given.
◍ Compare the processes of spermatogenesis and oogenesis. [8 marks].
Answer: a. both produce haploid cells / both produce (mature/male/female)
gametesb. both have mitosis at start/in epithelium / both involve mitosis and
meiosis;c. both have cell growth before meiosis;d. both involve
differentiation (to produce a specialised gamete);Oogenesis:a. eggs/ova
produced in the ovariesb. process starts during development of
embryo/fetusc. meiosis breaks occur in prophase I/ prophase II/ metaphase
IId. cytoplasm split unequally / larger cell and smaller cellse. one cell/egg
(per meiosis) / some become polar bodiesf. one gamete (usually) at a
time/per month/per menstrual cycleg. timing of release: on about Day 14/in
middle of menstrual cycle/at ovulationh. stops at
menopauseSpermatogenesis:a. sperm (atozoa) produced in the testesb.
, process starts during puberty/adolescencec. no breaks in meiosisd. equal
division of cytoplasme. four sperm (per meiosis) / all cells become spermf.
many/far more/(hundreds of) millions daily/at a time gametes producedg.
timing of release: continuously (from testis) / by ejaculation/intercourseh.
goes on (throughout adult life/until death)
◍ Alleles that are neither dominant nor recessive to one another, so both
alleles are always expressed in the phenotype..
Answer: Codominant
◍ Describe the consequences of the potential overproduction of offspring. [5
marks].
Answer: a. more (offspring) than the environment can support / carrying
capacity reachedb. increased mortality/lower life expectancy/more deaths;c.
competition (for resources) / struggle for survival;d. food/mates/nest
sites/territory/other example of resource shortage / exampleof greater
need;e. variation between members of population / example of variation;f.
better adapted more likely to survive / converse; (reject
Lamarckianstatements such as those who adapt survive)g. better adapted
reproduce / pass on (favourable) genes/traits / converse;h. natural selection /
(survival of fittest) leads to evolution
◍ The inheritance of a single gene.
Answer: Monohybrid inheritance
◍ Physical, behavioural, biochemical expression of an organisms genotype.
Answer: Phenotype
◍ Outline the processes that occur during the first division of meiosis. [6
marks].
Answer: a. (consists of) prophase, metaphase, anaphase and telophase;b.
chromosome number halved/reduced/(diploid) to haploid;c. homologous
chromosomes pair up/form a bivalent/synapsis in prophase; d. crossing over
between non-sister chromatids/chromatids of different homologues;e.
nuclear envelope breaks down (at end of prophase/start of metaphase);f.
tetrads/bivalents/homologous pairs move to/align on equator/cell
, centre/onmetaphase plate in metaphase; (accept homologous chromosomes
withoutpairs if pairing has already been described)g. attachment of spindle
fibres/microtubules to centromeres/kinetochores;h. (homologous)
chromosomes separate/pulled to opposite poles in anaphase;i. nuclear
envelopes reform/do not reform (because of meiosis II) in telophase; Accept
the above points in a series of annotated diagrams. Reject answers with
single chromatids forming pairs in metaphase or separating or moving to
opposite poles in anaphase.
◍ The type of genes an individual has.
Answer: Genotype
◍ Prior to cell division, chromosomes replicate. Explain the process of DNA
replication in prokaryotes. [8 marks].
Answer: a. DNA replication is semi-conservative;b. each (molecule formed)
has one new strand and one from parent molecule;c. helicase uncoils
DNA;d. helicase separates the two strands by breaking hydrogen bonds
betweenbases; (reject unzips as an alternative to uncoils but accept as
alternative toseparates if breakage of hydrogen bonds is included)e. RNA
primase adds primer / primase adds (short) length of RNA;f. DNA
polymerase III binds to/starts at (RNA) primer;g. DNA polymerase (III)
adds nucleotides/bases in a 5' → 3' direction;h. bases according to
complementary base pairing / A-T and C-G;i. (leading strand) built up
continuously (towards the replication fork);j. (lagging strand) built up in
pieces/short lengths/Okazaki fragments;k. DNA polymerase I removes
RNA/primers and replaces them with DNA;l. ligase seals gaps between
nucleotides/fragments/makes sugar-phosphatebonds;m. nucleoside
triphosphates provide the energy to add nucleotides;Accept the above points
in annotated diagrams.
◍ Outline outcomes of the human genome project. [4 marks].
Answer: a. complete human DNA/chromosomes sequenced;b. identification
of all human genes / find position/map (all) human genes;c. find/discover
protein structures/functions;d. find evidence for evolutionary
, relationships/human origins/ancestors;e. find mutations/base
substitutions/single nucleotide polymorphisms;f. find genes
causing/increasing chance of/develop test for/screen for diseases;g. develop
new drugs (based on base sequences) / new gene therapies;h. tailor
medication to individual genetic variation / pharmacogenomics;i. promote
international co-operation/global endeavours;
◍ Alles that is always expressed in the phenotype.
Answer: Dominant
◍ 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.
◍ Only expressed in the phenotype when homozygous.
Answer: Recessive
◍ both alleles are the same.
Answer: Homozygous
◍ Both alleles for a specific gene are different.
Answer: Heterozygous
◍ Position of a gene on a chromosome.
Answer: Loci
◍ A set of instructions for a specific polypeptide.
Answer: Gene
◍ Explain how skeletal muscle contracts. [8 marks].
7402-2 MARK SCHEME MS PRACTICE
EXAMINATION 2026 QUESTIONS
WITH ANSWERS GRADED A+
◍ Draw a labelled diagram of the human adult male reproductive system. [5
marks].
Answer: a. scrotum - shown around testes;b. testes/testis/testicles - shown
inside scrotum;c. epididymis - shown adjacent to testis and connected to
sperm duct;d. sperm duct/vas deferens - double line connecting
testis/epididymis to urethra; e. seminal vesicle - sac shown branched off
sperm duct (not off the urethra);f. prostate gland - shown positioned where
sperm duct connects with urethra; g. urethra - shown as double line linking
bladder to end of penis;h. penis - with urethra passing through it;Award [1]
for each structure clearly drawn and labelled that conforms to the italicized
guidelines given.
◍ Compare the processes of spermatogenesis and oogenesis. [8 marks].
Answer: a. both produce haploid cells / both produce (mature/male/female)
gametesb. both have mitosis at start/in epithelium / both involve mitosis and
meiosis;c. both have cell growth before meiosis;d. both involve
differentiation (to produce a specialised gamete);Oogenesis:a. eggs/ova
produced in the ovariesb. process starts during development of
embryo/fetusc. meiosis breaks occur in prophase I/ prophase II/ metaphase
IId. cytoplasm split unequally / larger cell and smaller cellse. one cell/egg
(per meiosis) / some become polar bodiesf. one gamete (usually) at a
time/per month/per menstrual cycleg. timing of release: on about Day 14/in
middle of menstrual cycle/at ovulationh. stops at
menopauseSpermatogenesis:a. sperm (atozoa) produced in the testesb.
, process starts during puberty/adolescencec. no breaks in meiosisd. equal
division of cytoplasme. four sperm (per meiosis) / all cells become spermf.
many/far more/(hundreds of) millions daily/at a time gametes producedg.
timing of release: continuously (from testis) / by ejaculation/intercourseh.
goes on (throughout adult life/until death)
◍ Alleles that are neither dominant nor recessive to one another, so both
alleles are always expressed in the phenotype..
Answer: Codominant
◍ Describe the consequences of the potential overproduction of offspring. [5
marks].
Answer: a. more (offspring) than the environment can support / carrying
capacity reachedb. increased mortality/lower life expectancy/more deaths;c.
competition (for resources) / struggle for survival;d. food/mates/nest
sites/territory/other example of resource shortage / exampleof greater
need;e. variation between members of population / example of variation;f.
better adapted more likely to survive / converse; (reject
Lamarckianstatements such as those who adapt survive)g. better adapted
reproduce / pass on (favourable) genes/traits / converse;h. natural selection /
(survival of fittest) leads to evolution
◍ The inheritance of a single gene.
Answer: Monohybrid inheritance
◍ Physical, behavioural, biochemical expression of an organisms genotype.
Answer: Phenotype
◍ Outline the processes that occur during the first division of meiosis. [6
marks].
Answer: a. (consists of) prophase, metaphase, anaphase and telophase;b.
chromosome number halved/reduced/(diploid) to haploid;c. homologous
chromosomes pair up/form a bivalent/synapsis in prophase; d. crossing over
between non-sister chromatids/chromatids of different homologues;e.
nuclear envelope breaks down (at end of prophase/start of metaphase);f.
tetrads/bivalents/homologous pairs move to/align on equator/cell
, centre/onmetaphase plate in metaphase; (accept homologous chromosomes
withoutpairs if pairing has already been described)g. attachment of spindle
fibres/microtubules to centromeres/kinetochores;h. (homologous)
chromosomes separate/pulled to opposite poles in anaphase;i. nuclear
envelopes reform/do not reform (because of meiosis II) in telophase; Accept
the above points in a series of annotated diagrams. Reject answers with
single chromatids forming pairs in metaphase or separating or moving to
opposite poles in anaphase.
◍ The type of genes an individual has.
Answer: Genotype
◍ Prior to cell division, chromosomes replicate. Explain the process of DNA
replication in prokaryotes. [8 marks].
Answer: a. DNA replication is semi-conservative;b. each (molecule formed)
has one new strand and one from parent molecule;c. helicase uncoils
DNA;d. helicase separates the two strands by breaking hydrogen bonds
betweenbases; (reject unzips as an alternative to uncoils but accept as
alternative toseparates if breakage of hydrogen bonds is included)e. RNA
primase adds primer / primase adds (short) length of RNA;f. DNA
polymerase III binds to/starts at (RNA) primer;g. DNA polymerase (III)
adds nucleotides/bases in a 5' → 3' direction;h. bases according to
complementary base pairing / A-T and C-G;i. (leading strand) built up
continuously (towards the replication fork);j. (lagging strand) built up in
pieces/short lengths/Okazaki fragments;k. DNA polymerase I removes
RNA/primers and replaces them with DNA;l. ligase seals gaps between
nucleotides/fragments/makes sugar-phosphatebonds;m. nucleoside
triphosphates provide the energy to add nucleotides;Accept the above points
in annotated diagrams.
◍ Outline outcomes of the human genome project. [4 marks].
Answer: a. complete human DNA/chromosomes sequenced;b. identification
of all human genes / find position/map (all) human genes;c. find/discover
protein structures/functions;d. find evidence for evolutionary
, relationships/human origins/ancestors;e. find mutations/base
substitutions/single nucleotide polymorphisms;f. find genes
causing/increasing chance of/develop test for/screen for diseases;g. develop
new drugs (based on base sequences) / new gene therapies;h. tailor
medication to individual genetic variation / pharmacogenomics;i. promote
international co-operation/global endeavours;
◍ Alles that is always expressed in the phenotype.
Answer: Dominant
◍ 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.
◍ Only expressed in the phenotype when homozygous.
Answer: Recessive
◍ both alleles are the same.
Answer: Homozygous
◍ Both alleles for a specific gene are different.
Answer: Heterozygous
◍ Position of a gene on a chromosome.
Answer: Loci
◍ A set of instructions for a specific polypeptide.
Answer: Gene
◍ Explain how skeletal muscle contracts. [8 marks].
