Question X
Question
3a.
b.
c.
Total
Piglet Porkers
Evidence for
Evidence for
Evidence for
Achieved
Achieved with Merit
Achieved with Excellence
One valid description interpreting the
Student
data.
compares
transcription
e.g.
 More transcription by the QQ genotype between QQ and
qq in at least two
at any ages/type of tissue/throughout
of the following:
compared with qq genotypes.
 Much more transcription by QQ
 Any type of
genotype in skeletal compared to qq
tissue
gentopye/slightly more transcription by

Skeletal
QQ genotype in cardiac than qq
tissue only
genotype.
 Cardiac
 In QQ genotypes, expression reduces
tissue only
with age in both skeletal and cardiac
whereas in qq genotypes expression
 3 vs 16 weeks
rises with age in skeletal but falls in
in any tissue
cardiac muscle.
Both descriptions correct.
Homozygous – the alleles of
a particular gene locus are
the same. i.e. QQ or qq
Recessive – an allele on an
autosome that is only
expressed in the organism
when two are present.
Description of effect on Explanation of one
Thorough understanding of several
regulatory region of
possible cause of the aspects of the regulatory region
gene.
increased
demonstrated and linked to increased
transcription rate.
transcription therefore growth factor
leading to increased growth in pigs.
e.g.
At least two causes explained.
e.g.
 Change shape of
enhancer/regulatory
 May change the
In the QQ genotype, mutant allele leads
gene/promoter
shape of
to increase in transcription rate and
sequence
regulatory
therefore additional growth factor
gene/enhancer
synthesized which stimulates muscle
genes which
growth in pigs.
increases the
binding of the
Caused by:
stimulating
chemical/transcripti
 May change the shape of regulatory
gene/enhancer genes which
on factors.
increases the binding of the
stimulating chemical/transcription
factors.
 May change the shape of the
promoter sequence which increases
affinity for RNA polymerase/enzymes
 Prevents production of
repressor/transcription factors
which inhibits the rate of transcription.
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