exam questions

Question 1

which cells/structures prevent the entry of pathogens into the body?

Answer 1

• platelets
• mucous membranes
• goblet cells

Question 2

which cells/structures act as a physical barrier to pathogens?

Answer 2

• platelets
• skin

Question 3

which cells/structures are involved in phagocytosis?

Answer 3

• phagosomes
• antigen presenting cells
• lysosomes
• neutrophils

Question 4

how does the malarial parasite bypass the body’s primary defences?

Answer 4

• pierces skin with mouth
• injects malaria into the blood

Question 5

what are the antibody molecules that are recognised by phagocyte receptors?

Answer 5

opsonins

Question 6

outline the processes that lead to the production of antibodies against unfamiliar bacterium (3 marks)

Answer 6

• T cells bind to B cells with complementary antigens
• clonal selection
• B cells undergo clonal expansion
• differentiate into plasma and memory cells

Question 7

suggest and explain one symptom of having a lack of mature B lymphocytes (2 marks)

Answer 7

• greater susceptibility to infection
• longer recovery
• no antibodies

Question 8

explain how genes and the environment cause animals to vary in their specific immune response (6 marks)

Answer 8

genes
- different alleles code for different antibodies
- mutation produces new alleles
- autoimmune disease eg lupus
- inherit genes that code for antibodies

environment
- exposure to different pathogens determines immune response
- vaccinations produce primary immune response
- allergies
- poor diet can impact immune system