The graph shows how the number of antibodies changed in an individbc-.ai6ppji 8g;b /uuual's blood ovu-ii8 pj6ba p;ugb/c.er time.

  Which human disease was the first to be eradicated by ,x7n nqlexs5xzq :)1sntc),d vaccination?

  Antibodies are proteins that bind to antigp 3d;v u2x4b vnxa;q(mens. Which cell expresses the genes for anti uxpa4;m2 (;qbd3vn xvbody production?

  Which is true for a zoonotic disease?

  Which of these does not contribute to antibi,f5g y1u9xfk hcnbaj+-en i5 9otic resistance?

  Which of the following statement(s) is/are true for plasma cellrd h79lnl; ;xns?
I.
Clones of B lymphocytes
II.
Produce large numbers of antibodies
III.
Have extensive rough endoplasmic reticulum

  Which is a correct des8+sxh pu gd;9ri 3r.gha9 b)nkcription of antigens?

The graph shows the typical immune response to two doses0s(rlytw 7cj2 of a vaccine



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State which type of molecule stimulates antibody production.

Distinguish between the primary and secondary responses.

Explain how vaccination leads to long-term immunity.

Antibodies are proteins with/h-b)rb inq a/arcb0p;* zm g3 a specific shape that are produced by B lymphocytes.3an/-b*/g0 b q)h brpmic;z ra
Describe how antibodies defend against pathogens.

The diagram shows how the effect of gy0 *moieqjww98qbw1 -wxx6 9c c)xm7i 33m hulrowing bacteria with different antibiotics can be investigated. A study was conducted to test the degree of antibiotmuoi6)h3wiqb 37lx19c -w0*w9cj mexwxqm y8ic resistance that bacteria from a hospital door handle had developed. Measurements of the zone of inhibition were taken every 3 days, for 15 days.



1.State which antibiotic is the least effective at preventing bacterial growth.

2.State two variables that must be controlled in this experiment, other than those already given.

3.1Identify the anomalous result from the study.

3.2Suggest how the anomalous result may have arisen.

4.Explain how natural selection can lead to antibiotic resistance in bacteria.

5.The researchers suggested that vancomycin could be used more extensively to treat bacterial infections. Discuss to what extent you agree with this.

  The diagram shows a red blood cell with thei- 0:hswnb-piuwx f6// gxu/ v A antigen.


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Which statement explains why a blood transfusion with blood group A cannot be given to someone with blood group O?

  Which row contains a cause and consequence of antibiotic r4wet. yq8z*8(zgds b1j+trx hesistance?The cause is?The Consequence i +bj 1gz(8th*yerx wz.q s8t4ds?

  This diagram shows the interaction between a helper T-cell and a B-lymphocyte prg csl/)(tkvif9 9m,.



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What is particle X?

  In blood donation, an acute hemolytic transfusion yktfj :9oj -2qreaction occurs when red blood cells are attacked by the recip k:t9y -qojj2fient’s immune system. Which property of red blood cells explains this response?

  Which statement is true about B-lymphoyw np5p.0dnt 5cytes in mammals?

  In a classroom investigation into the effects of her *wqb0k z)klnp9 3n:iobal remedies on bacterial infections, students selected a range of herbal teas, marketed as possessing “Immune System Boosting” properties. Teas each contained one wil:pz )k 30obk9qn*n main ingredient, in addition to other secondary ingredients, present in lower concentrations.
A concentrated solution of each tea was prepared and a 0.2 g mass of cotton wool was soaked in each.
A petri dish was prepared using nutrient agar gel and inoculated with a strain of Staphylococcus aureus. The masses of cotton wool were each placed on the petri dish, which was then incubated at 20
o
C for 5 days, after which the zone of inhibition for each mass of cotton wool was measured.


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The experiment was repeated 3 times, a mean and standard deviation was calculated. Results are shown below.


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1.1State the dependent variable in this investigation.

1.2Identify one control variable from the methodology.

2.1Based on the results, suggest which ingredient is most effective at inhibiting the growth of bacteria. Give a reason for your answer.

2.2State the TWO brands of tea whose results are unlikely to show statistically significant differences. Give a reason for your answer.

3.Calculate the size of the inhibition zone for EterniTea as a percentage of the size of that for ResisTea.  

4.Outline the techniques which should be employed in order to reduce risk when working with bacterial cultures.

5.1Identify a limitation of the methodology in allowing a valid comparison of each tea brand.

5.2State how the size of the error bars could be reduced.

  [Maximum mark: 15]
Swine fever is a highly contagious disease in pigs. The disease is classified into two types: African and classical. Classical swine fever (CSF) is caused by the classical swine fever virus (CSFV) and can be controlled by a live attenuated vaccine. This study presents the events that occurred after the intramuscular (IM) administration of a live attenuated marker vaccine, FlagT4Gv. Such a marker vaccine enables the identification of serum samples that have come from vaccinated animals rather than infected animals and therefore allows for immunological differentiation between infected and vaccinated pigs. The aim of this study was to determine how many days are needed post-vaccination before the pigs are protected against the virus. To test the pig’s immunity to the CSFV, the virulent CSFV (BICv) was introduced intranasally between 1 and 7 days after inoculation with the marker vaccine. The number of pigs that survived in each group was recorded, as was the mean time to death. One group, the mock group, was not inoculated with the marker vaccine but was exposed to the BICv.




[Source: Adapted from Holinka LG, O’Donnell V, Risatti GR, Azzinaro P, Arzt J, Stenfeldt C, et al. (2017) Early protection events in swine immunized with an experimental live attenuated classical swine fever marker vaccine, FlagT4G. PLoS ONE 12(5): e0177433. Retrieved October 27, 2022, from https://doi.org/10.1371/journal.pone.0177433. Copyright-free]
1.Calculate the percentage increase in mean time to death between the mock group and the group that was BICv challenged 2 days post inoculation with FlagT4Gv. Show your working.   
The presence of the virus was measured for a maximum of 21 days in each group of FlagT4Gv-inoculated animals, those challenged with the BICv 1 day, 2 days, 3 days, 5 days and 7 days after inoculation with FlagT4Gv as well as in the mock group. The level of BICv was recorded and the results are shown in the graph below. Numbers correspond exclusively to the presence of BICv which was determined by immunocytochemistry.


[Source: Adapted from Holinka LG, O’Donnell V, Risatti GR, Azzinaro P, Arzt J, Stenfeldt C, et al. (2017) Early protection events in swine immunized with an experimental live attenuated classical swine fever marker vaccine, FlagT4G. PLoS ONE 12(5): e0177433. Retrieved October 27, 2022, from https://doi.org/10.1371/journal.pone.0177433. Copyright-free]
2.1Based on the immunocytochemical data shown in the graph, identify the concentration of BICv 7 days post-challenge with BICv for the group infected 2 days after inoculation with FlagT4Gv.

2.2Explain the cause for the difference in viral levels between the group infected 2 days after inoculation and the group infected 3 days after inoculation.

3.Suggest a reason why data is not recorded after day seven, for the mock group and the group exposed to BICv one day after inoculation.

4.Determine the number of days post FlagT4Gv inoculation after which complete protection is achieved against BICv.

5.Describe the pattern of the results shown in the graph.

In a second experiment, tonsil tissue was collected from three different groups of pigs which had undergone different treatments, shown in the table below.



[Source: Adapted from Holinka LG, O’Donnell V, Risatti GR, Azzinaro P, Arzt J, Stenfeldt C, et al. (2017) Early protection events in swine immunized with an experimental live attenuated classical swine fever marker vaccine, FlagT4G. PLoS ONE 12(5): e0177433. Retrieved October 27, 2022, from https://doi.org/10.1371/journal.pone.0177433. Copyright-free]
The tissue was then examined using immunohistochemistry, which involves using monoclonal antibodies and fluorescent dyes to highlight any viruses present. The results from Groups 1, 2, and 3 are shown below.




FlagT4Gv in frozen sections of tonsil tissues from pigs either inoculated with FlagT4Gv or infected with BICv or both.
[Source: Adapted from Holinka LG, O’Donnell V, Risatti GR, Azzinaro P, Arzt J, Stenfeldt C, et al. (2017) Early protection events in swine immunized with an experimental live attenuated classical swine fever marker vaccine, FlagT4G. PLoS ONE 12(5): e0177433. Retrieved October 27, 2022, from https://doi.org/10.1371/journal.pone.0177433. Copyright-free]
6.Describe what can be seen in the tissue sections from each of the 3 groups.

7.Suggest reasons for the appearance of the tonsil tissue from both group 1 and group 3.

8.Discuss whether the data supports the hypothesis that inoculation with FlagT4Gv prevents infection with all types of swine fever.

[Maximum mark: 16]
1.Outline the importance of international cooperation in fighting infectious diseases.

2.Outline the role of monoclonal antibodies in home pregnancy tests.

3.Explain the specific immune response to a pathogen in terms of antibodies and lymphocytes.