A food scientist investigates the response to chemicals released into the air by food. Impulses are recorded from a sensory neurone that carries impulses from the receptors, and the saliva produced is collected for one minute.
| Concentration of airborne food chemical (mg m⁻³) | Impulse frequency in the sensory neurone (impulses s⁻¹) | Volume of saliva collected (cm³) |
|---|---|---|
| 0.0 | 0 | 0.2 |
| 0.4 | 18 | 0.5 |
| 0.8 | 31 | 0.7 |
| 1.2 | 43 | 1.0 |
Identify the stimulus, the receptor and the effector in this response.
Explain how the increase in concentration of the airborne food chemical causes the change in the volume of saliva collected.
135 exam-style questions on OCR GCSE Biology 3.1 Coordination and control – the nervous system, covering 3.1.1 Structure of the nervous system, 3.1.2 Coordinated response, 3.1.3 The reflex arc, 3.1.4 Structure of the eye, 3.1.5 Defects of the eye, 3.1.6 Structure and function of the brain, 3.1.7 Difficulties of investigating brain function, and 3.1.8 Limitations in treating nervous system damage. Each one has a worked solution and a mark scheme showing where the marks go.