Vaccination is another way of reducing the transmission of infectious diseases such as TB. The BCG vaccine is used to help control the spread of TB. This vaccine contains a weakened strain of the pathogen that causes TB. The BCG vaccine stimulates the development of antigen-specific memory T-lymphocytes. Explain how memory T-lymphocytes provide protection from TB in a person who has been given a BCG vaccination. ............................................................................................................................................... . ............................................................................................................................................... . ............................................................................................................................................... . ............................................................................................................................................... . ............................................................................................................................................... . .........................................................................................................................................

Biology

IGCSE&ALevel

CAIE

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

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