Which is NOT used (as an isolation method) to isolate a particular bacterial type from a mixed sample?

The photo below demonstrates the results for Methyl Red test. Which one is POSITIVE (A or B)?   

In his initial 1907 case, Alois Alzhemier identified abnormal nerve cells and fiber cluster in the cerebral cortex using the new silver –staining methods of autopsy. Which of the following is the neuropathological hallmark of Alzheimer’s disease? 

Which of the following conditions is BEST characterized by excessive anxiety and worry occurring more days than not for at least 6 months about several events or activities (such as work or school performance)?

   Which of the following structures is a COMT inhibitor?     

A 55-year-old female has been diagnosed by her GP with anxiety. She requires an anxiolytic drug which does not cause sedation.  Which of the following anxiolytic drugs would be MOST appropriate? 

 Which of the following patients would be MOST suitable for a non-prescription supply of Nytol® one a night (diphenyhydramine 50mg) tablets?  

 Amitriptyline is a frequently used tricyclic antidepressant (TCA).  It is metabolised in the liver to form nortriptyline. Which of the following statements about amitriptyline and nortriptyline is NOT correct?

The serotonin system is involved in many processes in psychiatry including, most prominently mood, sleep and psychosis. In which of the following structure is serotonin primarily synthesised? 

Describing the underlying chemistry, rationalise the use of DOPA-decarboxylase inhibitors.    (5 Marks)