Immunity and vaccinationEdexcel A-Level Biology A: Subtopic test

1. 1
   Newborn babies have antibodies against measles in their blood at birth, received from their mothers across the placenta. The level of these antibodies falls to almost zero by about six months. In the UK the first measles vaccine dose is given at about twelve months.

   (a)

   Which type of immunity do the newborn babies have at birth?

   [1 mark]

   • ANatural active
   • BArtificial active
   • CNatural passive
   • DArtificial passive

   (b)

   Why is the first measles vaccine not given to newborn babies?

   [1 mark]

   • AMaternal antibodies could destroy the vaccine antigens before the baby's own immune system responds
   • BNewborn babies have no B cells
   • CThe vaccine would pass to the mother across the placenta
   • DBabies cannot make memory cells until six years old

   (c)

   Explain why the antibodies received from the mother give the baby only temporary protection.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A hospital records four cases. Person W recovers from chickenpox. Person X is given the hepatitis B vaccine. Person Y, bitten by a rabid dog, is injected with rabies antibodies. Person Z, a baby, receives antibodies from her mother's breast milk.

   (a)

   Which person has developed artificial active immunity?

   [1 mark]

   • APerson W
   • BPerson X
   • CPerson Y
   • DPerson Z

   (b)

   The immunity of which people does not involve the production of memory cells?

   [1 mark]

   • AW only
   • BX only
   • CW and X
   • DY and Z

   (c)

   Explain why the injection gives person Y protection straight away but only for a short time.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A volunteer was given a vaccine on day 0 and a booster dose of the same vaccine on day 28. After the first dose the antibody concentration in the blood peaked at 20 arbitrary units (au) on day 14 and had fallen to 6 au by day 28. After the booster it peaked at 110 au on day 35 and was still above 40 au on day 120.

   (a)

   Describe the differences between the antibody response to the first dose and the response to the booster dose.

   [3 marks]

   (b)

   Explain these differences in terms of the cells involved in the immune response.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A health agency recommends that pregnant women are vaccinated against whooping cough in late pregnancy so that their newborn babies are protected. The babies are then given their own whooping cough vaccine at two months old.

   (a)

   Explain how vaccination of the mother protects the newborn baby, and why the baby still needs to be vaccinated at two months.

   [6 marks]

   (b)

   Compare active immunity and passive immunity, giving a natural and an artificial example of each.

   [6 marks]

   Total for question 4: 12 marks

End of questions