HEY GUYS! I'm just having a complete sense of blankness as to how I would answer this question, anyone that knows PLEASE HELP. 
In what way is anxiety experienced as a ‘normal’ part of everyday life different from the experience of anxiety that characterises an anxiety disorder?
Anxiety in everyday life is adaptive; a severe anxiety response can be useful in the short term to help to equip us to deal with threatening/dangerous situations. Physiologically, it is like the flight-fight response and therefore makes us more alert and our reactions faster. Mild-moderate levels also makes us more alert and improve our ability to cope.
By contrast, anxiety associated with an anxiety disorder is not adaptive and is usually counter-productive and disabling, causing extreme distress and dysfunction. It is often accompanied by intense physiological sensations and responses.