describe the sequence of events that occurs during a primary immune response with reference to the roles of: • macrophages • B-lymphocytes, including plasma cells • T-lymphocytes, limited to T-helper cells and T-killer cells

outline the main stages in the process of cell signalling leading to specific responses: • secretion of specific chemicals (ligands) from cells • transport of ligands to target cells • binding of ligands to cell surface receptors on target cells

recognise and draw red blood cells, monocytes, neutrophils and lymphocytes from microscope slides, photomicrographs and electron micrographs