The graph shows how the number of antibodies cha-ca nh9b l3z:enged in an individual's blood overbza3cnl9:e -h time.

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

  Which human disease was th8(zh/q a7o rlne first to be eradicated by vaccination?

  Antibodies are proteins that bind to antigens. Which cell exp+dh5im 9)nc)o3r a rdkresses the genes for antibrdd rka95)hmc o+)i3n ody production?

  Which is true for a zoonotic disem41 xdad gqzv93ulzc7 5pi(h4ase?

  Which of these does not cq)vr);ro0g0 k) e krn zsy.+irontribute to antibiotic resistance?

  Which of the following statement(s) is/are t c:ene(:n z1ejrue for plasma cells?
I.  Clones of B lymphocytes
II.  Produce large numbers of antibodies
III.  Have extensive rough endoplasmic reticulum

  Which is a correct description of ane5o1fvvkcencdk v8. -q 1fa :gxoq;52tigens?

The graph shows the typical immune response to two doses of a )z- 3dfmi5 kilvaccine.

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 th,pb7 rm9fpkg .at are produced by B lymphocytes. . rf7mpkb,pg9
Describe how antibodies defend against pathogens.

The diagram shows how the efgvd sh7 4r*j6u04iuyifect of growing bacteria with different antibiotics can be investiga gyh0iu6jr74ivd4s* u ted. 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 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 blood cell with the A antigenuzk/k,2c p812ciy *cvulu1 k w.



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

  Which row contains a cau z+s6/ n0yozkq (knegnfr 8k55se and consequence of antibiotic resistance?

  This diagram shows the interaction between a helper T-cell and a B-lymphocytmuws:/n +j-9zgj3j2 5uur3otnevr ,j e.

  In blood donation, an acute hemolytic transfusion reaction occurs when red bloodk,) fjjv)t/i;sr hqw;5*k szr cells are attacked by the recipient’s immune system. Which property of red blood cekr)svjq trjz i)kh5w /*;fs;,lls explains this response?

  Which statement is true about B-lymphocytm(ox)-sj 9cqf0a q *mles in mammals?

n a classroom investigation into the effects of herbal remedies on bacterial inas0+r jq)9a cyn6; -hkxmx u5u5lf 5tsfections, 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 iqh5t5 5- sk+lx;asnru6umc a0j9yxf) n 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 pigs. The disease is clas kgmo)1ky7l e,6tz md, p)5adfsified 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 markeraem, kd6gkp)m7 1ol,y tfd )z5 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 in fighx vor c8-9 ezc;g6p 2np-nl jwp4s6t9xting infectious diseases.sxp nv48cnz9 -9xopj -gt2wlp;6rc6e
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.