What you'll learn
How organisms detect and respond to change.
Coordination
- The nervous system: receptors, neurones, synapses and reflex arcs.
- Hormones and the endocrine system (e.g. insulin, adrenaline).
Homeostasis
- Control of blood glucose and temperature.
- Plant hormones (auxins) and tropisms (phototropism, gravitropism).
Exam tips
- Learn the reflex arc in order: receptor → sensory → relay → motor → effector.
- Compare nervous (fast) and hormonal (slower, longer) responses.
Common mistakes
- Confusing sensory and motor neurones.
- Muddling insulin and glucagon.