The graph shows how the number of antibodies changed in an individual's bloodv* z c3)azw*-ytw,dye overv zy-t) a3e,dww** ycz time.

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

  Which human disease wa,l og )+o,r nb 1lkclr 5uhd:n-rtd,cf6xg7c7s the first to be eradicated by vaccination?

  Antibodies are proteins that bind to antigens. Which cell exp74agv1ojq; *w hwsy8e resses the genes for antibod8we o7 wya *4;hgjsqv1y production?

  Which is true for a zoonotic dikoe4 khqt/*9qu0gb s 7sease?

  Which of these does nonjl 27yys)0t uv i:+cdt contribute to antibiotic resistance?

  Which of the following statement(s) is/are eu:o6a902yke *dkhs ztrue for plasma cells?
I.  Clones of B lymphocytes
II.  Produce large numbers of antibodies
III.  Have extensive rough endoplasmic reticulum

  Which is a correct desc.(6lnt*c may(gs/l rh ription of antigens?

The graph shows the typical immune response to two doses1 *2e1pjui2ag)sclns 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 specific shape that are producewohm*7c ap 1c+f8y) on5nvlv:d by B lymphocytes.n :vf*w)oa58c mvl7+1h pco ny
Describe how antibodies defend against pathogens.

The diagram shows how the effect of growing back8o;,hvd nud7teria with different antibiotics can be investigated. A study was conducted to test the degree of antibiotic resistance that bacteria from a hospital door had;8,7 uvnh dokndle 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.(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 , pt*)tr cavw0k*m*mu blood cell 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 zid+ sal*,np 8( zcv)yd3;wdoresistance?

  This diagram shows the interaction between a helper T-cell and a B-lymphocyte. r )fe *hu,xfd3

  In blood donation, an acute hemolytvd.v 5r. xne,i-cjq7kic transfusion reaction occurs when red blood cells are attacked by the recipient’s immune system. Which property of red bloodv7- c,5edxir.n v.qjk cells explains this response?

  Which statement is true about B-lymphocytes ini.duq)3p(yt c jt7ujxc ci;q8 l.s,(h mammals?

n a classroom investigation into the effects oc/m; 0k.p.jv y3jdbm9c7p sybf herbal remedies on bacterial infections, students selected a range of herbal teas, marketed as possessing “Immune System Boosting” properties. Teas each contained one main ingredient, in addition to other secondary ingredients, present in lower concentrations.my.cvy0bb dkjp.m c/7 p ;93js
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 pigs. The diseaklp3 f59q 1 kt i*a(4votcxn2kse 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 virctlt qfapo 3415kxv9i 2k kn(*us. 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.


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 of international cooperation 2cz1vcmjj01hlefw16 zikfd,7c0)g1v kc ps * in fighting infectious diseas ph1fc0fw1k6c,zcj m0 vlck2 71je*gd z vs)1ies.
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.