Question 1

The diagram represents the general structure of an antibody.

Which of the numbered part(s) of the diagram represent the part of the antibody that has the same sequence of amino acids in all antibodies?

  A  

1, 2, and 3

  B  

only 1 and 2

  C  

only 2 and 3

  D  

only 1

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Question 2

Which statements correctly describe lymphocytes?

1 - each B lymphocyte has the ability to make several types of antibody molecules

2 - some B lymphocytes and T lymphocytes become memory cells

3 - plasma cells secrete antibodies into the blood plasma

4 - some T lymphocytes stimulate macrophages to kill infected cells

  A  

1, 2, 3, and 4

  B  

1, 2, and 3 only

  C  

1 and 4 only

  D  

2, 3, and 4 only

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Question 3

Bacteria that infect skin wounds can become resistant to the antibiotic commonly used to kill them.

What explains how these bacteria could become resistant to the antibiotic?

  A  

exposure to the antibiotic causes a change in the bacterial cell wall, preventing the antibiotic from working

  B  

other bacteria that normally protect the skin against infection are killed by the antibiotic, allowing the infectious bacteria to survive

  C  

random mutations in DNA allow some of the bacteria to survive in the presence of the antibiotic

  D  

the antibiotic causes the bacterial DNA to mutate, allowing the bacteria to survive in the presence of the antibiotic

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Question 4

Which are specific immune responses?

1 - phagocytosis

2 - production of antibodies

3 - effect of histamine

  A  

1 only

  B  

2 only

  C  

1 and 3 only

  D  

2 and 3 only 

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Question 5

The statements refer to the disease tuberculosis (TB):

1 - the pathogen lives inside human cells so is not accessible to the immune system

2 - the bacterial pathogen reproduces slowly

3 - the pathogen is not very sensitive to antibiotics

Which explains why antibiotic treatment for TB takes a long time?

  A  

1, 2, and 3

  B  

1 and 2 only

  C  

1 and 3 only

  D  

2 and 3 only

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Question 6

What are the function(s) of T lymphocytes during an immune response?

1 - destroy infected body cells

2 - differentiate into memory cells

3 - secrete antibodies

  A  

1 only

  B  

3 only

  C  

1 and 2 only

  D  

2 and 3 only

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Question 7

What happens when people are injected with dead bacteria?

  A  

B lymphocytes produce antibodies

  B  

B lymphocytes produce antigens

  C  

T lymphocytes produce antibodies

  D  

T lymphocytes produce antigens

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Question 8

Antibodies can act in a number of ways to protect the body from pathogenic bacteria.

What will not occur following antigen-antibody binding?

  A  

agglutination of bacteria to reduce their spread

  B  

increased susceptibility to phagocytosis

  C  

neutralisation of toxins to make them harmless


  D  

secretion of histamine to produce an allergic reaction

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Question 9

Breast milk produced by the mother for a new-born baby contains antibodies.

What do these antibodies provide?

  A  

artificial active immunity

  B  

artificial passive immunity

  C  

natural active immunity

  D  

natural passive immunity

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Question 10

When a body cell is infected by a pathogen, what is the correct immune response?

  A  

killer T cells punch holes in infected cells, releasing antibodies

  B  

killer T cells release cytokines, infected body cells release antibodies

  C  

memory cells release antibodies, killer T cells secrete cytokines

  D  

helper T cells release cytokines, plasma cells release antibodies

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Question 11

In an investigation into the immune response, a volunteer was exposed to two different antigens, X and Y.

The relative antibody concentration in the blood was measured at regular intervals over 60 days.

The graph shows the time when the volunteer was exposed to each antigen and the antibody concentration against time for antigens X and Y.

What is the explanation for the results displayed on the graph?

  A  

a primary and secondary immune response against antigen X occurred, with the memory B lymphocytes inhibiting the secondary immune response against antigen Y

  B  

a primary immune response to antigen Y occurred and memory B lymphocytes specific to antigen Y enhanced the secondary immune response to antigen X

  C  

memory B lymphocytes specific to antigen X enabled a secondary immune response to occur; different B lymphocytes were activated for a primary immune response for antigen Y

  D  

plasma cells remaining from the first exposure to antigen X undergo rapid clonal selection to produce high levels of antibody against antigen X and lower levels of antibody against antigen Y

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Question 12

Which plant disease is caused by a pathogen from the kingdom Protoctista?

  A  

black sigatoka in bananas

  B  

ring rot in tomatoes


  C  

tobacco mosaic disease


  D  

tomato late blight


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