Syllabus concepts to know

• C3.1.1 System integration
• C3.1.2 Cells, tissues, organs and body systems as a hierarchy of subsystems that are integrated in a multicellular living organism
• C3.1.3 Integration of organs in animal bodies by hormonal and nervous signalling and by transport of materials and energy
• C3.1.4 The brain as a central information integration organ
• C3.1.5 The spinal cord as an integrating centre for unconscious processes
• C3.1.6 Input to the spinal cord and cerebral hemispheres through sensory neurons
• C3.1.7 Output from the cerebral hemispheres to muscles through motor neurons
• C3.1.8 Nerves as bundles of nerve fibres of both sensory and motor neurons
• C3.1.9 Pain reflex arcs as an example of involuntary responses with skeletal muscle as the effector
• C3.1.10 Role of the cerebellum in coordinating skeletal muscle contraction and balance
• C3.1.11 Modulation of sleep patterns by melatonin secretion as a part of circadian rhythms
• C3.1.12 Epinephrine (adrenaline) secretion by the adrenal glands to prepare the body for vigorous activity
• C3.1.13 Control of the endocrine system by the hypothalamus and pituitary gland
• C3.1.14 Feedback control of heart rate following sensory input from baroreceptors and chemoreceptors
• C3.1.15 Feedback control of ventilation rate following sensory input from chemoreceptors
• C3.1.16 Control of peristalsis in the digestive system by the central nervous system and enteric nervous system
• C3.1.17 Observations of tropic responses in seedlings (HL)
• C3.1.18 Positive phototropism as a directional growth response to lateral light in plant shoots (HL)
• C3.1.19 Phytohormones as signalling chemicals controlling growth, development and response to stimuli in plants (HL)
• C3.1.20 Auxin efflux carriers as an example of maintaining concentration gradients of phytohormones (HL)
• C3.1.21 Promotion of cell growth by auxin (HL)
• C3.1.22 Interactions between auxin and cytokinin as a means of regulating root and shoot growth (HL)
• C3.1.23 Positive feedback in fruit ripening and ethylene production (HL)