Organs integrate into a coordinated body. This HL lesson covers C3.1 Integration of body systems and C3.2 Defence against disease.
You will compare nervous and hormonal control, map key brain regions, and study innate and adaptive immunity, vaccines and monoclonal antibodies.
Work through each screen, answer the questions as you go (some are wordy, some are calculations) and collect ⭐ stars. Press Start when you are ready.
The body is coordinated by interacting nervous (fast, electrical, precise) and endocrine (slower, chemical, widespread) systems, with feedback loops.
Key brain regions:
Innate defences are fast and non-specific: skin and mucous barriers, blood clotting, and phagocytes.
Adaptive immunity is specific: B-lymphocytes make antibodies, and memory cells give a faster, stronger secondary response. Vaccines exploit this, and high uptake gives herd immunity.
Monoclonal antibodies are identical antibodies from one B-cell clone; because each binds a single antigen, they are used in diagnosis (e.g. pregnancy tests) and therapy.
Epidemiology tracks disease spread. Concerns include antibiotic resistance, HIV/AIDS (a retrovirus that destroys helper T-cells) and zoonoses that jump from animals to humans.
Sort each process into the correct control or defence system.
Match each structure or term to its role.
C3.1 (HL): nervous vs hormonal control; cerebellum, medulla, hypothalamus/pituitary
C3.2: innate vs adaptive immunity; memory cells and the secondary response
C3.2 (HL): monoclonal antibodies; epidemiology, HIV, zoonoses, resistance
Skills: cardiac output = stroke volume × heart rate
Press Finish to see your score.
You have worked through Theme C: Interaction — Body Systems & Defence for IB Diploma Biology. 🎉
Your stars: 0 / 0
Next: test yourself in the Verify stage.