As this is a 4 mark question you are expected to make 4 points; 1 for each mark This question is asking you to describe differences. You do not need to explain why there are differences. You should compare phagocytes to lymphocytes to highlight the differences. Example Answer:Phagocytes are white blood cells which circulate in the body. They engulf pathogens and then use a range of enzymes inside the cell to destroy the pathogen. Whereas, lymphocytes recognise specific molecules on the surface of pathogens called antigens. They then produce antibodies which are molecules specific to the pathogen which makes the pathogens stick together. Phagocytes and lymphocytes work together as a part of the immune response to pathogens.