The graph shows how the number of antibodiesn-p wv tt,h93bqsh9k6 changed in an individual's blood overt-6v9,hqstk b3nhw9p time.

What is the most likely cause of the change in antibody levels at point X?

  Which human disease 0atz(c*1c p9v yb0ec64gz qdv 16 5khsxe6 coxwas the first to be eradicated by vaccination?

  Antibodies are proteinszlzv i- 9,elgr hw; w8lqy2c1* that bind to antigens. Which cell expresses the genes for antiblel z q,9g2zlcwyw 1v-rih8;*ody production?

  Which is true for a za o8df so/;3w*n6 rwkfoonotic disease?

  Which of these does not contribute to antibiaehsk 505ol zb7v4uv7 k x.mz(otic resistance?

  Which of the following state(jpv+ zl/5 -jzf1aqws:tol4h ment(s) is/are true for plasma cells?
I.  Clones of B lymphocytes
II.  Produce large numbers of antibodies
III.  Have extensive rough endoplasmic reticulum

  Which is a correct descriptionay tqqvt .ubu4 n1gpris-n;(:4 gf)7r of antigens?

The graph shows the typicalhc ih7 lwz;x 6lgn*r)a fr7c i8u6knmq :j,8n7 immune response to two doses of a vaccine.

1.State which type of molecule stimulates antibody production.
2.Distinguish between the primary and secondary responses.
3.Explain how vaccination leads to long-term immunity.

Antibodies are proteins with a specko6sk*0- omoiific shape that are produced by B lymphocytes. sk6-kom*io 0o
Describe how antibodies defend against pathogens.

The diagram shows how the effect of growing bacteria with did)khhp cz+- 9 ewx/wezv h4s42fferent antibiotics can be investigated. A study was conducted to test the degree of antibiotic resistance that bacteria from a hospital door handle had developed. Measurements of the zone of inhibition were takenc-se+4k2pxzw h)v/h 9dze h4w 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.(1)Identify the anomalous result from the study.
(2)Suggest 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 celli 4za7ydel 8vl4 mki3v: *bdn; with the A antigen.



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 resistance?47wv.to b rj;d

  This diagram shows th w+kty:sv:7c we interaction between a helper T-cell and a B-lymphocyte.

  In blood donation, an acute hemolytic transfusion reaction occurs k.;ei9je c(qu*w k.uxyx1 ;vwwhen red blood cells are attacked by the recipient’s immune system. Which property of red blo. xukkcx(.1*9e;w;we uqvy ij od cells explains this response?

  Which statement is true about B-lymphocytes y97(wxxucyc7g v( *an4np1wmin mammals?

n a classroom investigation into the effects 9;6u/h6glh4(3diuz equg d yh+a0 ext of herbal remedies on bacterial infections, students selected a range of herbal teas, marketed as possessing qh;ee giug0uu4h3 dzl/dxt6h+6y9 (a “Immune System Boosting” properties. Teas each contained one 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.

Swine fever is a highly contagious disease in pihedf(: 64grwxgs. 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 intrdr4:g (ewhx6f anasally 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.


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.



2.(1)Based 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)Explain 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.


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.



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.

1.Outline the importance ofpt yz d*21s;bpvpkpgd5;(ux07 6d dfw international cooperation in fighting infectious diseases. tsgpb;xf d7(y 50zvd6;kddwu2pp 1p *
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.