Adult stem cells are undifferentiated cells that are found in most animal tissues. Adult stem cells can divide by mitosis throughout their lifespan to form identical stem cells (self-renewal) or to form cells that can differentiate into the functioning cells of that tissue. Cell type $$$\mathbf{Y}$$$ shown in Fig. 4.1 releases molecules with antigen binding sites. Name the molecules released by cell type $$$\mathbf{Y}$$$. .........................................................................................................................................

Biology

IGCSE&ALevel

CAIE

Exam No：9700_w24_qp_22 Year：2024 Question No：4(f)

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