chapter 12

Question 1

Suggest two ways to minimise the spread of an outbreak of plague.

Answer 1

two from
stay keep indoors / increase ventilation / wear masks (1)
measures to, exclude / not attract / kill, rats / fleas (1)
strict / immediate quarantine for persons with symptoms (1)

Question 2

State how a clone of potatoes could be produced for this investigation

Answer 2

tissue culture / micropropagation 

Question 3

explain why it is important to carry out this procedure under aseptic conditions.

Answer 3

reduces, microorganisms / contamination

Question 4

State the role of cytokines

Answer 4

attract / AW , (named) phagocytes ✓

Question 5

State the role of opsonins in phagocytosis.

Answer 5

bind to / AW , pathogens / foreign cells / antigens , and increase phagocytosis / recognition by phagocytes ✓

Question 6

Outline the processes that lead to the production of antibodies against an unfamiliar bacterium.

Answer 6

B cells / lymphocytes, have, antigen receptor / carry antibody, on surface, specific / complementary to, only one antigen (1)

selected / activated, B cell, proliferates / clones / divides by mitosis (1)

forms / differentiates into, plasma / effector, cells (1)
which secrete antibodies specific / complementary, to antigen (1)

Question 7

Explain how helper T cells act to speed up these processes.

Answer 7

(helper T cells) stimulated by antigen- presenting cells (1)
release, cytokines / interleukin 2 (1) stimulate B-cell, proliferation / mitosis / clonal expansion (1)