UPDATED AQA BIOLOGY 2024/2025 PAPER 3
QUESTIONS WITH VERIFIED ANSWERS ALREADY
GRADED A+
'Having thymine at nucleotide position 16 519 in Group T causes
an increase in ability to exercise for longer.' Evaluate this
conclusion. Use all the data in this question. - RIGHT ANSWER
-Yes : group T have increased CS activity for krebs cycle
group T have increased VO2 max so more oxygen transport for
exercise
No : no correlation between CS activity and VO2 max on figure 6
So may not be thymine causing the increase
A journalist who read this investigation concluded that ipilimumab
improved the treatment of MM. Do the data in Table 2 support this
conclusion? Give reasons for your answer. - RIGHT ANSWER -Yes -
Median ST increases by 2.1 months
Percentage of patients showing reduction in tumours increased
from 10.3% to 15.2%
no - no stats test so results may be due to chance
A student analysed Table 3 and concluded that Trexall was
effective in reducing pain in arthritis patients. Evaluate the
student's conclusion. - RIGHT ANSWER -For : Pain decreases more
with trexall
Against : Small sample size
No stats test
,A student concluded from Figure 4 and Figure 5 that training has a
positive effect on VO2max and CS activity. Evaluate the student's
conclusion - RIGHT ANSWER -Both groups did show an increase in
both VO2 max and CS activity after the training programme
However no stats test to show if the difference was significant
And the results may not be applicable to females as they arent
included in the sample
Aquaporins are channel proteins that allow the diffusion of water
across membranes. One type of aquaporin, called PIP1, can also
transport carbon dioxide molecules across membranes. Figure 6
shows the structure of a water molecule and of a carbon dioxide
molecule. They are drawn to the same scale. Suggest two reasons
why water molecules and carbon dioxide molecules can both pass
through PIP1. - RIGHT ANSWER -They are both small molecules
They both have a similar shape which is complementary to
aquaporins
Binding of insulin leads to an increase in the rate of respiration in
cells such as osteoblasts. Explain how. - RIGHT ANSWER -the
insulin leads to more channel proteins for glucose
so more glucose enters the cell for respiration
Binding of one molecule of oxygen to haemoglobin makes it easier
for a second oxygen molecule to bind. Explain why. - RIGHT
,ANSWER -Binding of the first oxygen changes the tertiary
structure of hemoglobin
Which uncovers another binding site
Caffeine affects the autonomic nervous system. Suggest how
caffeine could account for the results of Group I in Figure 3 at 60
minutes.( increase HR) - RIGHT ANSWER -The caffeine means that
more action potentials are sent along the sympathetic nervous
system to the SA node which causes the increase in heart rate
CENP-W is involved in the formation of spindle fibres in mitosis.
Spindle fibres are made of molecules of a protein called tubulin.
The scientists treated cells in a culture with small interfering RNA
(siRNA). This siRNA causes RNA interference of expression of the
CENP-W gene. The scientists took samples of cells at 0, 48 and 72
hours after adding the siRNA. They then used gel electrophoresis
to separate CENP-W and tubulin from these samples. Figure 5
shows the results of the electrophoresis. The size of each band is
proportional to the amount of CENP-W or tubulin present. Suggest
how the siRNA produced these results - RIGHT ANSWER -siRNA
destroys CENP-W mRNA
Which prevents translation of CENP-W
As CENP-W reduces the production of tubilin also reduces
Describe how the human immunodeficiency virus (HIV) is
replicated once inside helper T cells (TH cells). - RIGHT ANSWER
-RNA converted to DNA using reverse transcriptase when HIV
attaches to CD4 receptors on a TH cell
,The DNA is inserted into the host chromosome
The viral DNA is transcribed to make viral mRNA
The HIV mRNA is translated into new viral proteins
Describe how you could make a temporary mount of a piece of
plant tissue to observe the position of starch grains in the cells
when using an optical (light) microscope. - RIGHT ANSWER -Add a
drop of water to a glass slide
Obtain a thin section of the plant tissue and put it on the slide
Add iodine to stain
Lower a cover slip using a mounted needle
Describe the role of saprobionts in the nitrogen cycle. - RIGHT
ANSWER -They use enzymes to decompose proteins
Which releases ammonium compounds
evaluate the importance of PIP1 in the movement of carbon
dioxide and water through leaves of poplar trees. - RIGHT ANSWER
-Loss of PIP reduces water and carbon dioxide movement
The difference is significant as standard deviations dont overlap
Loss of PIP has a greater effect on carbon dioxide transport
Evaluate the use of artificial fertilisers on grain-producing crops in
India. - RIGHT ANSWER -Using more fertilizer resulted in less of a
response over time
QUESTIONS WITH VERIFIED ANSWERS ALREADY
GRADED A+
'Having thymine at nucleotide position 16 519 in Group T causes
an increase in ability to exercise for longer.' Evaluate this
conclusion. Use all the data in this question. - RIGHT ANSWER
-Yes : group T have increased CS activity for krebs cycle
group T have increased VO2 max so more oxygen transport for
exercise
No : no correlation between CS activity and VO2 max on figure 6
So may not be thymine causing the increase
A journalist who read this investigation concluded that ipilimumab
improved the treatment of MM. Do the data in Table 2 support this
conclusion? Give reasons for your answer. - RIGHT ANSWER -Yes -
Median ST increases by 2.1 months
Percentage of patients showing reduction in tumours increased
from 10.3% to 15.2%
no - no stats test so results may be due to chance
A student analysed Table 3 and concluded that Trexall was
effective in reducing pain in arthritis patients. Evaluate the
student's conclusion. - RIGHT ANSWER -For : Pain decreases more
with trexall
Against : Small sample size
No stats test
,A student concluded from Figure 4 and Figure 5 that training has a
positive effect on VO2max and CS activity. Evaluate the student's
conclusion - RIGHT ANSWER -Both groups did show an increase in
both VO2 max and CS activity after the training programme
However no stats test to show if the difference was significant
And the results may not be applicable to females as they arent
included in the sample
Aquaporins are channel proteins that allow the diffusion of water
across membranes. One type of aquaporin, called PIP1, can also
transport carbon dioxide molecules across membranes. Figure 6
shows the structure of a water molecule and of a carbon dioxide
molecule. They are drawn to the same scale. Suggest two reasons
why water molecules and carbon dioxide molecules can both pass
through PIP1. - RIGHT ANSWER -They are both small molecules
They both have a similar shape which is complementary to
aquaporins
Binding of insulin leads to an increase in the rate of respiration in
cells such as osteoblasts. Explain how. - RIGHT ANSWER -the
insulin leads to more channel proteins for glucose
so more glucose enters the cell for respiration
Binding of one molecule of oxygen to haemoglobin makes it easier
for a second oxygen molecule to bind. Explain why. - RIGHT
,ANSWER -Binding of the first oxygen changes the tertiary
structure of hemoglobin
Which uncovers another binding site
Caffeine affects the autonomic nervous system. Suggest how
caffeine could account for the results of Group I in Figure 3 at 60
minutes.( increase HR) - RIGHT ANSWER -The caffeine means that
more action potentials are sent along the sympathetic nervous
system to the SA node which causes the increase in heart rate
CENP-W is involved in the formation of spindle fibres in mitosis.
Spindle fibres are made of molecules of a protein called tubulin.
The scientists treated cells in a culture with small interfering RNA
(siRNA). This siRNA causes RNA interference of expression of the
CENP-W gene. The scientists took samples of cells at 0, 48 and 72
hours after adding the siRNA. They then used gel electrophoresis
to separate CENP-W and tubulin from these samples. Figure 5
shows the results of the electrophoresis. The size of each band is
proportional to the amount of CENP-W or tubulin present. Suggest
how the siRNA produced these results - RIGHT ANSWER -siRNA
destroys CENP-W mRNA
Which prevents translation of CENP-W
As CENP-W reduces the production of tubilin also reduces
Describe how the human immunodeficiency virus (HIV) is
replicated once inside helper T cells (TH cells). - RIGHT ANSWER
-RNA converted to DNA using reverse transcriptase when HIV
attaches to CD4 receptors on a TH cell
,The DNA is inserted into the host chromosome
The viral DNA is transcribed to make viral mRNA
The HIV mRNA is translated into new viral proteins
Describe how you could make a temporary mount of a piece of
plant tissue to observe the position of starch grains in the cells
when using an optical (light) microscope. - RIGHT ANSWER -Add a
drop of water to a glass slide
Obtain a thin section of the plant tissue and put it on the slide
Add iodine to stain
Lower a cover slip using a mounted needle
Describe the role of saprobionts in the nitrogen cycle. - RIGHT
ANSWER -They use enzymes to decompose proteins
Which releases ammonium compounds
evaluate the importance of PIP1 in the movement of carbon
dioxide and water through leaves of poplar trees. - RIGHT ANSWER
-Loss of PIP reduces water and carbon dioxide movement
The difference is significant as standard deviations dont overlap
Loss of PIP has a greater effect on carbon dioxide transport
Evaluate the use of artificial fertilisers on grain-producing crops in
India. - RIGHT ANSWER -Using more fertilizer resulted in less of a
response over time
