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2024 AQA AS BIOLOGY PAPER 1 EXAM QUESTIONS WITH CORRECT ANSWERS
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2024 AQA AS BIOLOGY PAPER 1 EXAM QUESTIONS WITH CORRECT ANSWERS
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2024 AQA AS BIOLOGY PAPER 1EXAM QUESTIONS WITH CORRECT
ANSWERS
Describe a biochemical test to show that raffinose solution contains a non-
reducing sugar. - CORRECT-ANSWERSFirst heat the sample with an acid in a
water bath and neutralise, then heat with Benedict solution in a water bath
for five minutes. A positive test should produce a red precipitate.
Human papilloma virus (HPV) is the main cause of cervical cancer. A vaccine
has been developed to protect girls and women from HPV. Describe how
giving this vaccine leads to production of antibody against HPV - CORRECT-
ANSWERS1. Vaccine/it contains antigen (from HPV);
2. Displayed on antigen-presenting cells;
3. Specific helper T cell (detects antigen and) stimulates specific B cell;
4. B cell divides/goes through mitosis/forms clone to give plasma cells;
5. B cell/plasma cell produces antibody;
Doctors investigated whether it was better to give two or three doses of the
HPV vaccine. They determined the mean concentration of antibody against
HPV in blood samples from girls who were given either two or three doses of
the vaccine.
• Girls given two doses received an initial vaccination, followed by a second
at 6 months.
• Girls given three doses received an initial vaccination, followed by a
second at 1 month and a third at 6 months.
The doctors measured the concentration of antibody each month. The results
are shown in Figure 5.
What do these results suggest about whether it is better to give two or three
doses of the vaccine? Give reasons for your answer - CORRECT-ANSWERS1.
Two (doses) because got more antibody; 2. With three doses, second
dose/dose at 1 month doesn't lead to production of any more antibody (than
the twodose group)/get same/similar response; 3. Three doses would be
more expensive/less popular with parents/girls (and serves no purpose);
, The doctors carried out a statistical test to determine whether the antibody
concentrations were significantly different in girls given two doses of the
vaccine, compared with those given three doses. They determined the mean
concentrations of antibody 9 months after the first dose of vaccine.
What statistical test should the doctors have used? Give the reason for your
choice. - CORRECT-ANSWERSt-test, because comparing two means;
There is genetic diversity within HPV.
Give two ways doctors could use base sequences to compare different types
of HPV. - CORRECT-ANSWERS1. Compare (base sequences of) DNA;
2. Look for mutations/named mutations (that change the base sequence);
3. Compare (base sequences of) (m)RNA;
Chromosomes line up on the equator of the mitotic spindle in... - CORRECT-
ANSWERSmetaphase
Suggest why the development of a monopolar mitotic spindle would prevent
successful mitosis. - CORRECT-ANSWERS1. No separation of
chromatids/chromosomes/centromeres;
2. Chromatids/chromosomes all go to one pole/end/sides of cell/not pulled to
opposite poles;
3. Doubles chromosome number in cell/one daughter cell gets no
chromosomes or chromatids;
A student who saw these results concluded that in any future trials of this
kinesin inhibitor with people, a concentration of 100 nmol dm-3 would be
most appropriate to use.
Do these data support the student's conclusion? Give reasons for your
answer - CORRECT-ANSWERS1. (No, because) at 100 there are still some
(7%) cancer cells dividing/undergoing mitosis;
2. So, cancer not destroyed/may continue to grow/spread/form tumours;
3. Best concentration may be between 100 and 1000/need trials between
100 and 1000;
4. This research in culture, don't know effect of KI on people;
5. (Yes, because) above 100 produces little increase in % of cells not
dividing/undergoing mitosis/at 100, most (93%) cancer cells unable to
divide/dead;
6. Above 100 may be harmful (to body);
7. Higher concentrations more expensive;
8. (above 100) will have more effect on (rapidly dividing) cancer cells;
Explain the arrangement of phospholipids in a cell-surface membrane. -
CORRECT-ANSWERSPhospholipids are arranged in a phospholipid bilayer.
The hydrophobic fatty acid tails point away from the water and the
hydrophilic heads attract the water.
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