The bladder is the organ in the body used to store urine. When cells divide uncontrollably in the bladder, a tumour develops. This can lead to bladder cancer. The BCG vaccine has been used to treat bladder cancer. The BCG vaccine is introduced into the bladder. The tumour cells take up the weakened pathogens in the vaccine and act as antigen-presenting cells. (i) Name the process used by the tumour cells to take up the weakened pathogens. ................................................................................................................................. (ii) Suggest how antigen presentation by tumour cells stimulates an immune response that leads to the destruction of the tumour cells. ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . .................................................................................................................................

Biology

IGCSE&ALevel

CAIE

Exam No：9700_w24_qp_21 Year：2024 Question No：3(d)

Answer:

11.1.1 describe the mode of action of phagocytes (macrophages and neutrophils)

11.1.2 explain what is meant by an antigen (see 4.1.3) and state the difference between self antigens and non-self antigens

11.1.3.1 macrophages

11.1.3.2 B-lymphocytes, including plasma cells

11.1.3.3 T-lymphocytes, limited to T-helper cells and T-killer cells

11.1.4 explain the role of memory cells in the secondary immune response and in long-term immunity