Immune Response

IGCSE Edexcel Biology
2.62 White Blood Cells
Key Concept: Phagocytes ingest pathogens and lymphocytes produce specific antibodies.

Section A: Phagocytes

1. Describe the steps of phagocytosis. [3]

Section B: Lymphocytes

2. Explain how lymphocytes help destroy pathogens. [3]
3. Explain why antibodies are specific. [2]
4. Give one difference between phagocytes and lymphocytes. [2]
Total marks: 10

Mark Scheme

1. Pathogen recognized, engulfed, digested by enzymes (any three) [3]
2. Lymphocytes produce antibodies that bind to pathogens and help destroy them [3]
3. Antibody shape matches a specific antigen [2]
4. Phagocytes ingest pathogens; lymphocytes make antibodies (or similar) [2]