Biology Revision

The search for better health Discuss the difficulties of defining the terms 'health' and 'diseases': Health is hard to define because it incorporates many things and some can be very subjective. Such as, biological, psychological and social well-being. Disease is similarly difficult to define because it is a state of impairment functioning or poor health. It depends on an individual's normal level of functioning and on what they expect their quality of life to be. …

…the brain to coordinate the behaviour. Behaviour may be a simple reaction, such as blinking the eyes in response to an object coming too close. Or it may be a complex activity such as building a nest, catching prey or learning to perform a task. It is important to interpret signals by the brain correctly for the coordination of behaviour because it makes sure that the correct response is does...see p.41 for better wording...