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SingaporeBiology

Infectious Disease and Immunity

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do antibiotics treat bacterial infections, and why is antibiotic resistance a growing problem?

Explain how antibiotics treat bacterial infections and how antibiotic resistance arises and spreads
A focused answer to the H2 Biology Infectious Disease and Immunity outcome on antibiotics. How antibiotics target bacteria-specific processes, why they do not work against viruses, how resistance arises by mutation and selection, how it spreads (including by plasmids), and how to slow it.
8 min answer →

How does antibody structure suit its function, and why is the secondary immune response faster and stronger than the primary?

Describe the structure and function of antibodies and explain the primary and secondary immune responses
A focused answer to the H2 Biology Infectious Disease and Immunity outcome on antibodies and memory. The structure of an antibody and how it suits binding, the ways antibodies destroy pathogens, and why the secondary response is faster and stronger because of memory cells.
9 min answer →

What are pathogens, and how do the structures and life cycles of bacteria and viruses cause infectious disease?

Describe the structure of bacteria and viruses as pathogens and explain how they cause infectious disease
A focused answer to the H2 Biology Infectious Disease and Immunity outcome on pathogens. The structure of bacteria and viruses, how each causes disease (toxins and tissue damage versus host-cell hijacking), routes of transmission, and the meaning of a pathogen.
8 min answer →

How does the adaptive immune system mount a specific response to a particular pathogen using lymphocytes?

Describe the adaptive immune response, including the roles of T and B lymphocytes in the cell-mediated and humoral responses
A focused answer to the H2 Biology Infectious Disease and Immunity outcome on adaptive immunity. Antigens and antigen presentation, the cell-mediated response by T lymphocytes, the humoral response by B lymphocytes, clonal selection, and the production of plasma and memory cells.
9 min answer →

How does the body defend itself against pathogens before the adaptive immune response is mounted?

Describe the innate (non-specific) defences, including barriers, phagocytosis and the inflammatory response
A focused answer to the H2 Biology Infectious Disease and Immunity outcome on innate immunity. The physical and chemical barriers, phagocytosis by neutrophils and macrophages, the inflammatory response, and why innate immunity is fast but non-specific.
8 min answer →

How does vaccination produce immunity without illness, and how does herd immunity protect a population?

Explain how vaccination produces active immunity and how herd immunity protects a population, and distinguish active and passive immunity
A focused answer to the H2 Biology Infectious Disease and Immunity outcome on vaccination. How a vaccine produces active immunity through the primary response and memory cells, the difference between active and passive immunity, and how herd immunity protects a population.
8 min answer →